Terms starting with letter u

Color key: WebIDL CSS Markup HTTP

u (markup element) §: Defined in HTML; Referenced in HTML Accessibility API Mappings 1.0, ARIA in HTML, WebVTT: The Web Video Text Tracks Format
"u8" (value for AudioSampleFormat WebIDL enumeration) §: Defined in WebCodecs; Referenced in Linear PCM WebCodecs Registration
"u8-planar" (value for AudioSampleFormat WebIDL enumeration) §: Defined in WebCodecs
ua (concept) §: Defined in CSS 2.1; Referenced in CSS View Transitions 2, Compositing 1, CSS Snapshot 2022, CSS Snapshot 2023, CSS Animations 1, CSS Box Model 3, CSS Containment 1, CSS Display 3, CSS Font Loading 3, CSS GCPM 3, CSS Masking 1, CSS Scrollbars Styling 1, CSS User Interface 3, CSS View Transitions 1, CSS Viewport 1
UADataValues (WebIDL dictionary) §: Defined in User-Agent Client Hints; Related terms: UADataValues.architecture, UADataValues.bitness, UADataValues.brands, UADataValues.formFactors, UADataValues.fullVersionList, UADataValues.mobile, UADataValues.model, UADataValues.platform, UADataValues.platformVersion, UADataValues.uaFullVersion, UADataValues.wow64; see also WebIDLPedia
UADataValues.uaFullVersion (WebIDL dictionary member) §: Defined in User-Agent Client Hints
UALowEntropyJSON (WebIDL dictionary) §: Defined in User-Agent Client Hints; Related terms: UALowEntropyJSON.brands, UALowEntropyJSON.mobile, UALowEntropyJSON.platform; see also WebIDLPedia
"udp" (value for RTCIceProtocol WebIDL enumeration) §: Defined in WebRTC 1.0
"udp" (value for RTCIceServerTransportProtocol WebIDL enumeration) §: Defined in WebRTC 1.0
UDPMessage (WebIDL dictionary) §: Defined in Direct Sockets API; Related terms: UDPMessage.data, UDPMessage.dnsQueryType, UDPMessage.remoteAddress, UDPMessage.remotePort; see also WebIDLPedia
UDPSocket (WebIDL interface) §: Defined in Direct Sockets API; Related terms: UDPSocket.closed, UDPSocket.opened, WebIDL constructor constructor(), UDPSocket.close(); see also WebIDLPedia
UDPSocketOpenInfo (WebIDL dictionary) §: Defined in Direct Sockets API; Related terms: UDPSocketOpenInfo.localAddress, UDPSocketOpenInfo.localPort, UDPSocketOpenInfo.readable, UDPSocketOpenInfo.remoteAddress, UDPSocketOpenInfo.remotePort, UDPSocketOpenInfo.writable; see also WebIDLPedia
UDPSocketOptions (WebIDL dictionary) §: Defined in Direct Sockets API; Related terms: UDPSocketOptions.dnsQueryType, UDPSocketOptions.ipv6Only, UDPSocketOptions.localAddress, UDPSocketOptions.localPort, UDPSocketOptions.receiveBufferSize, UDPSocketOptions.remoteAddress, UDPSocketOptions.remotePort, UDPSocketOptions.sendBufferSize; see also WebIDLPedia
ui-monospace (CSS value for <generic-family>, font-family property ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
ui-rounded (CSS value for <generic-family>, font-family property ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
ui-sans-serif (CSS value for <generic-family>, font-family property ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
ui-serif (CSS value for <generic-family>, font-family property ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
UIEvent (WebIDL interface) §: Defined in UI Events; Referenced in DOM, HTML, Long Animation Frames API, CSS Spatial Navigation 1; Related terms: UIEvent.detail, UIEvent.sourceCapabilities, UIEvent.view, UIEvent.which, new UIEvent(type, eventInitDict), UIEvent.initUIEvent(typeArg, bubblesArg, cancelableArg, viewArg, detailArg); see also WebIDLPedia
new UIEvent(type, eventInitDict) (WebIDL constructor) §: Defined in UI Events
UIEventInit (WebIDL dictionary) §: Defined in UI Events; Referenced in CSS Spatial Navigation 1; Related terms: UIEventInit.detail, UIEventInit.sourceCapabilities, UIEventInit.view; see also WebIDLPedia
"uint" (value for GPUTextureSampleType WebIDL enumeration) §: Defined in WebGPU; Referenced in WebGPU Shading Language
"uint16" (value for GPUIndexFormat WebIDL enumeration) §: Defined in WebGPU
Uint16Array (WebIDL interface) §: Defined in Web IDL; Referenced in WebXR Meshing API 1, Web Cryptography API, Web Neural Network API, WebXR Depth Sensing; see also WebIDLPedia
%Uint16Array% (WebIDL interface) §: Defined in ECMAScript; see also WebIDLPedia
"uint16x2" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint16x4" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint32" (value for GPUIndexFormat WebIDL enumeration) §: Defined in WebGPU
"uint32" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint32" (value for MLOperandDataType WebIDL enumeration) §: Defined in Web Neural Network API
Uint32Array (WebIDL interface) §: Defined in Web IDL; Referenced in Encoding, WebXR Mesh Detection, Gamepad Extensions, Web Cryptography API, WebGPU, Web Neural Network API; see also WebIDLPedia
%Uint32Array% (WebIDL interface) §: Defined in ECMAScript; see also WebIDLPedia
"uint32x2" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint32x3" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint32x4" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint64" (value for MLOperandDataType WebIDL enumeration) §: Defined in Web Neural Network API
"uint8" (value for MLOperandDataType WebIDL enumeration) §: Defined in Web Neural Network API
Uint8Array (WebIDL interface) §: Defined in Web IDL; Referenced in Encoding, Fetch, Web Bluetooth, Compression Streams, Digital Credentials, Direct Sockets API, Web Serial API, Loading Signed Exchanges, File API, Indexed DB 3.0, Service Workers, Web Audio API, Web Cryptography API, Web MIDI API, Web Neural Network API, WebTransport; see also WebIDLPedia
%Uint8Array% (WebIDL interface) §: Defined in ECMAScript; see also WebIDLPedia
Uint8ClampedArray (WebIDL interface) §: Defined in Web IDL; Referenced in HTML, Web Cryptography API; see also WebIDLPedia
%Uint8ClampedArray% (WebIDL interface) §: Defined in ECMAScript; see also WebIDLPedia
"uint8x2" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"uint8x4" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
ul (markup element) §: Defined in HTML; Referenced in CSS Lists 3, HTML Accessibility API Mappings 1.0, ARIA in HTML, Publication Manifest, WAI-ARIA, WAI-ARIA; Related terms: markup attribute compact, markup attribute type
ULongRange (WebIDL dictionary) §: Defined in Media Capture and Streams; Related terms: ULongRange.max, ULongRange.min; see also WebIDLPedia
ultimate originating element (concept) §: Defined in Selectors 4; Referenced in CSS Values 5, CSS Containment 3, CSS Pseudo-Elements 4
"ultra-condensed" (value for CanvasFontStretch WebIDL enumeration) §: Defined in HTML
ultra-condensed (CSS value for font-width ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
"ultra-expanded" (value for CanvasFontStretch WebIDL enumeration) §: Defined in HTML
ultra-expanded (CSS value for font-width ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
unable to close browser (concept for [[errors]] ) §: Defined in WebDriver BiDi
unable to set cookie (concept for [[errors]] ) §: Defined in WebDriver BiDi
unable to set file input (concept for [[errors]] ) §: Defined in WebDriver BiDi
unauthenticated response (concept) §: Defined in Mixed Content
SmartCardReaderStateFlagsIn.unavailable (WebIDL dictionary member) §: Defined in Web Smart Card API
SmartCardReaderStateFlagsOut.unavailable (WebIDL dictionary member) §: Defined in Web Smart Card API
SmartCardReaderStateFlagsIn.unaware (WebIDL dictionary member) §: Defined in Web Smart Card API
"unbounded" (value for XRReferenceSpaceType WebIDL enumeration) §: Defined in WebXR Device API; Referenced in WebXR Layers API 1
UncalibratedMagnetometer (WebIDL interface) §: Defined in Magnetometer; Related terms: UncalibratedMagnetometer.x, UncalibratedMagnetometer.xBias, UncalibratedMagnetometer.y, UncalibratedMagnetometer.yBias, UncalibratedMagnetometer.z, UncalibratedMagnetometer.zBias, new UncalibratedMagnetometer(sensorOptions); see also WebIDLPedia
new UncalibratedMagnetometer(sensorOptions) (WebIDL constructor) §: Defined in Magnetometer
uncapturederror (event for GPUDevice ) §: Defined in WebGPU
GPUPrimitiveState.unclippedDepth (WebIDL dictionary member) §: Defined in WebGPU
GPUCanvasContext.unconfigure() (WebIDL operation) §: Defined in WebGPU
"unconfigured" (value for CodecState WebIDL enumeration) §: Defined in WebCodecs
uncredentialed-prefetch (concept for Supports-Loading-Mode ) §: Defined in Prerendering Revamped
undefined (WebIDL interface) §: Defined in Web IDL; Referenced in Console, DOM, Federated Credential Management API, Fetch, File System, Fullscreen API, WebXR Anchors, WebXR Plane Detection, Notifications API, requestStorageAccessFor API, The Storage Access API, Element Capture, Streams, Test Utils, URL, URL Pattern, The Capture-Handle Actions Mechanism, Web NFC API, IceTransport Extensions for WebRTC, WebAssembly JavaScript Interface: Content Security Policy, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, WebAssembly JavaScript Interface: Type Reflection, Web Bluetooth, Web Bluetooth Scanning, WebSockets, Attribution Reporting, Background Sync, Cookie Store API, Digital Goods API, Direct Sockets API, File and Directory Entries API, Fenced Frame, Idle Detection API, Prerendering Revamped, HTML Sanitizer API, Prioritized Task Scheduling, Web Serial API, Shared Storage API, Storage Buckets API, Private State Token API, Protected Audience, HTMLVideoElement.requestVideoFrameCallback(), Web App Launch Handler API, Web Preferences API, Web Smart Card API, WebHID API, WebUSB API, Audio Output Devices API, Badging API, Capture Handle - Bootstrapping Collaboration when Screensharing, Clipboard API and events, Compute Pressure 1, Credential Management 1, CSS Animation Worklet API, CSS Animations 1, CSS Font Loading 3, CSS Fonts 4, CSS Layout API 1, CSS Spatial Navigation 1, CSS Painting API 1, CSS Properties and Values API 1, CSS Typed OM 1, CSS View Transitions 1, CSSOM, CSSOM View, EditContext API, Encrypted Media Extensions, File API, Filter Effects 1, Generic Sensor API, Geolocation API, Indexed DB 3.0, JSON-LD 1.1 Processing Algorithms and API, Media Source Extensions™, Media Capture from DOM Elements, Region Capture, Media Capture and Streams, Media Session, MediaStream Recording, Orientation Sensor, Payment Handler API, Payment Request API 1.1, Performance Timeline, Picture-in-Picture, Pointer Events, Pointer Lock 2.0, Presentation API, Remote Playback API, Reporting API, requestIdleCallback() Cooperative Scheduling of Background Tasks, Resize Observer, Resource Timing, Screen Capture, Screen Orientation, Screen Wake Lock API, Selection API, Service Workers, UI Events, User Timing, VirtualKeyboard API, WebAssembly JavaScript Interface, Web Animations, Web Animations 2, Web Share API, Web Audio API, WebCodecs, WebGPU, Web MIDI API, Web Neural Network API, WebRTC Encoded Transform, Identity for WebRTC 1.0, WebRTC 1.0, WebTransport, WebXR Hit Test, WebXR Device API, WebXR Layers API 1, XMLHttpRequest; see also WebIDLPedia
globalThis.undefined (WebIDL attribute) §: Defined in ECMAScript
under (CSS value for ruby-position ) §: Defined in CSS Ruby Annotation Layout 1
under (CSS value for text-underline-position ) §: Defined in CSS Text Decoration 3 , CSS Text Decoration 4; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
under (CSS value for text-emphasis-position ) §: Defined in CSS Text Decoration 3 , CSS Text Decoration 4; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
under (concept) §: Defined in CSS Writing Modes 3 , CSS Writing Modes 4; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Inline Layout 3, CSS Rhythmic Sizing, CSS Text Decoration 3, CSS Text Decoration 4, CSS User Interface 4
underline (CSS value for text-decoration-line ) §: Defined in CSS Text Decoration 3 , CSS Text Decoration 4; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Syntax 3
underline (CSS value for text-decoration ) §: Defined in CSS 2.2; Referenced in WebVTT: The Web Video Text Tracks Format
UnderlineStyle (WebIDL enumeration) §: Defined in EditContext API; Related terms: value dashed, value dotted, value none, value solid, value wavy; see also WebIDLPedia
TextFormat.underlineStyle (WebIDL attribute) §: Defined in EditContext API
TextFormatInit.underlineStyle (WebIDL dictionary member) §: Defined in EditContext API
UnderlineThickness (WebIDL enumeration) §: Defined in EditContext API; Related terms: value none, value thick, value thin; see also WebIDLPedia
TextFormat.underlineThickness (WebIDL attribute) §: Defined in EditContext API
TextFormatInit.underlineThickness (WebIDL dictionary member) §: Defined in EditContext API
underlying buffer (concept for BufferSource ) §: Defined in Web IDL; Referenced in File System, Streams, Web Neural Network API, WebTransport
UnderlyingSink (WebIDL dictionary) §: Defined in Streams; Related terms: UnderlyingSink.abort, UnderlyingSink.close, UnderlyingSink.start, UnderlyingSink.type, UnderlyingSink.write; see also WebIDLPedia
UnderlyingSinkAbortCallback (WebIDL callback) §: Defined in Streams
UnderlyingSinkCloseCallback (WebIDL callback) §: Defined in Streams
UnderlyingSinkStartCallback (WebIDL callback) §: Defined in Streams
UnderlyingSinkWriteCallback (WebIDL callback) §: Defined in Streams
UnderlyingSource (WebIDL dictionary) §: Defined in Streams; Related terms: UnderlyingSource.autoAllocateChunkSize, UnderlyingSource.cancel, UnderlyingSource.pull, UnderlyingSource.start, UnderlyingSource.type; see also WebIDLPedia
UnderlyingSourceCancelCallback (WebIDL callback) §: Defined in Streams
UnderlyingSourcePullCallback (WebIDL callback) §: Defined in Streams
UnderlyingSourceStartCallback (WebIDL callback) §: Defined in Streams
AudioRenderCapacityEvent.underrunRatio (WebIDL attribute) §: Defined in Web Audio API
AudioRenderCapacityEventInit.underrunRatio (WebIDL dictionary member) §: Defined in Web Audio API
underscore (CSS value for caret-shape ) §: Defined in CSS User Interface 4
underspecified storage partition (concept for [[errors]] ) §: Defined in WebDriver BiDi
globalThis.unescape(string) (WebIDL operation) §: Defined in ECMAScript
"unfilterable-float" (value for GPUTextureSampleType WebIDL enumeration) §: Defined in WebGPU; Referenced in WebGPU Shading Language
unforced break (concept) §: Defined in CSS Fragmentation 3 , CSS Fragmentation 4; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Overflow 4
unforgeable (concept) §: Defined in Web IDL
unforgeable property name (concept) §: Defined in Web IDL
unfrozen (concept) §: Defined in Page Lifecycle
unhandledrejection (event for Window, WorkerGlobalScope interface ) §: Defined in HTML; Referenced in Streams, Web IDL, CSS View Transitions 1
Unicameral (concept) §: Defined in Internationalization Glossary
"unicase" (value for CanvasFontVariantCaps WebIDL enumeration) §: Defined in HTML
unicase (CSS value for font-variant-caps ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
unicode (CSS value for font-variant-emoji ) §: Defined in CSS Fonts 4; Referenced in CSS Snapshot 2023
unicode (concept) §: Defined in Internationalization Glossary; Referenced in Shared Storage API
RegExp.unicode (WebIDL attribute) §: Defined in ECMAScript
unicode bidi algorithm (concept) §: Defined in Internationalization Glossary
Unicode code point (concept) §: Defined in Internationalization Glossary; Referenced in CSS Custom Highlight API 1
unicode locale (concept) §: Defined in Internationalization Glossary
Unicode locale extension sequence (concept) §: Defined in ECMAScript Internationalization API
unicode normalization form c (concept) §: Defined in Internationalization Glossary
unicode normalization form d (concept) §: Defined in Internationalization Glossary
unicode normalization form kc (concept) §: Defined in Internationalization Glossary
unicode normalization form kd (concept) §: Defined in Internationalization Glossary
unicode-bidi (CSS property) §: Defined in CSS Writing Modes 3 , CSS Writing Modes 4 , CSS 2.1 , CSS 2.2; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Cascading 3, CSS Cascading 4, CSS Cascading 5, CSS Lists 3, CSS Overflow 4, CSS Pseudo-Elements 4, CSS Ruby Annotation Layout 1, CSS Text 3, CSS Text 4, CSS Typed OM 1, CSS User Interface 4, Filter Effects 1, WebVTT: The Web Video Text Tracks Format; Related terms: CSS value bidi-override, CSS value embed, CSS value isolate, CSS value isolate-override, CSS value normal, CSS value plaintext
unicode-range (CSS descriptor for @font-face ) §: Defined in CSS Fonts 4; Referenced in CSS Syntax 3
CSSFontFaceDescriptors.unicode-range (WebIDL attribute) §: Defined in CSS Fonts 4
<unicode-range-token> (CSS type) §: Defined in CSS Syntax 3
UnicodeEscape (algorithm) §: Defined in ECMAScript
UnicodeMatchProperty (algorithm) §: Defined in ECMAScript; Referenced in Regular Expression Pattern Modifiers for ECMAScript
UnicodeMatchPropertyValue (algorithm) §: Defined in ECMAScript; Referenced in Regular Expression Pattern Modifiers for ECMAScript
CSSFontFaceDescriptors.unicodeRange (WebIDL attribute) §: Defined in CSS Fonts 4
FontFace.unicodeRange (WebIDL attribute) §: Defined in CSS Font Loading 3
FontFaceDescriptors.unicodeRange (WebIDL dictionary member) §: Defined in CSS Font Loading 3
RegExp.unicodeSets (WebIDL attribute) §: Defined in ECMAScript
GPUBufferUsage.UNIFORM (WebIDL constant) §: Defined in WebGPU
"uniform" (value for GPUBufferBindingType WebIDL enumeration) §: Defined in WebGPU; Referenced in WebGPU Shading Language
union (concept for set ) §: Defined in Infra; Referenced in HTML, Attribution Reporting, Prefetch, Compute Pressure 1, Publication Manifest; Related terms: concept flattened member types, concept member types
union type (concept) §: Defined in Web IDL
IDBIndex.unique (WebIDL attribute) §: Defined in Indexed DB 3.0
IDBIndexParameters.unique (WebIDL dictionary member) §: Defined in Indexed DB 3.0
ChildBreakToken.[[unique id]] (internal slot) §: Defined in CSS Layout API 1
FragmentResult.[[unique id]] (internal slot) §: Defined in CSS Layout API 1
LayoutChild.[[unique id]] (internal slot) §: Defined in CSS Layout API 1
LayoutFragment.[[unique id]] (internal slot) §: Defined in CSS Layout API 1
unique identifier (concept) §: Defined in EPUB 3.3
CSSUnitValue.unit (WebIDL attribute) §: Defined in CSS Typed OM 1
unit map (concept for sum value ) §: Defined in CSS Typed OM 1
HIDReportItem.unitExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitFactorCurrentExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitFactorLengthExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitFactorLuminousIntensityExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitFactorMassExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitFactorTemperatureExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitFactorTimeExponent (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.unitSystem (WebIDL dictionary member) §: Defined in WebHID API
SVGAngle.unitType (WebIDL attribute) §: Defined in SVG 2
SVGLength.unitType (WebIDL attribute) §: Defined in SVG 2
universal selector (concept) §: Defined in CSS 2.1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
universal selector (concept) §: Defined in Selectors 4; Referenced in CSSOM
universal syntax definition (concept) §: Defined in CSS Properties and Values API 1; Referenced in CSS Variables 2, CSS Variables 1, Web Animations
Unix epoch (concept) §: Defined in High Resolution Time; Referenced in Notifications API, Topics API, Shared Storage API, Storage Buckets API
"unknown" (value for ConnectionType WebIDL enumeration) §: Defined in Network Information API
"unknown" (value for BarcodeFormat WebIDL enumeration) §: Defined in Accelerated Shape Detection in Images
"unknown" (value for PaymentComplete WebIDL enumeration) §: Defined in Payment Request API 1.1
"unknown" (value for GPUDeviceLostReason WebIDL enumeration) §: Defined in WebGPU
"unknown" (value for RTCDtlsRole WebIDL enumeration) §: Defined in WebRTC Statistics
"unknown" (value for RTCIceRole WebIDL enumeration) §: Defined in WebRTC 1.0
SmartCardReaderStateFlagsOut.unknown (WebIDL dictionary member) §: Defined in Web Smart Card API
unknown -webkit- pseudo-elements (concept) §: Defined in Selectors 4; Referenced in CSS Conditional 4
"unknown-reader" (value for SmartCardResponseCode WebIDL enumeration) §: Defined in Web Smart Card API
UnknownError (exception) §: Defined in Web IDL; Referenced in Web Bluetooth, Web Bluetooth Scanning, Web Serial API, Web Smart Card API, MediaStream Image Capture, Indexed DB 3.0, Region Capture, MediaStream Recording, Web Audio API, Web Authentication, WebRTC 1.0
unlinkable disclosure (concept) §: Defined in Verifiable Credentials Data Model v2.0: A type of selective disclosure where presentations cannot be correlated between verifiers.
unload (event for Window ) §: Defined in HTML; Referenced in Portals, Beacon
unload event end time (concept for document unload timing info ) §: Defined in HTML
unload event start time (concept for document unload timing info ) §: Defined in HTML
"unloaded" (value for FontFaceLoadStatus WebIDL enumeration) §: Defined in CSS Font Loading 3
unloaded (concept for Document ) §: Defined in MiniApp Lifecycle
"unloaded" (value for GlobalState WebIDL enumeration) §: Defined in MiniApp Lifecycle
"unloaded" (value for PageState WebIDL enumeration) §: Defined in MiniApp Lifecycle
PerformanceNavigationTiming.unloadEventEnd (WebIDL attribute) §: Defined in Navigation Timing 2
PerformanceTiming.unloadEventEnd (WebIDL attribute) §: Defined in Navigation Timing 2
PerformanceNavigationTiming.unloadEventStart (WebIDL attribute) §: Defined in Navigation Timing 2
PerformanceTiming.unloadEventStart (WebIDL attribute) §: Defined in Navigation Timing 2
unloading (concept for Document ) §: Defined in MiniApp Lifecycle
unloading document cleanup steps (concept) §: Defined in HTML; Referenced in Fullscreen API, Web NFC API, WebDriver BiDi, Compute Pressure 1, File API, Media Capture and Streams, Picture-in-Picture, Screen Orientation, Service Workers, Web Locks API, Web Audio API, WebRTC 1.0
unlock() (concept for Keyboard ) §: Defined in Keyboard Lock
Keyboard.unlock() (WebIDL operation) §: Defined in Keyboard Lock
ScreenOrientation.unlock() (WebIDL operation) §: Defined in Screen Orientation; Referenced in Prerendering Revamped
"unlocked" (value for ScreenIdleState WebIDL enumeration) §: Defined in Idle Detection API
GPUBuffer.unmap() (WebIDL operation) §: Defined in WebGPU
"unmapped" (value for GPUBufferMapState WebIDL enumeration) §: Defined in WebGPU
unmute (event) §: Defined in Media Capture and Streams
PressureObserver.unobserve() (WebIDL operation) §: Defined in Compute Pressure 1
IntersectionObserver.unobserve(target) (WebIDL operation) §: Defined in Intersection Observer; Referenced in HTML
ResizeObserver.unobserve(target) (WebIDL operation) §: Defined in Resize Observer
unordered set of unique space-separated tokens (concept) §: Defined in HTML; Referenced in Web Application Manifest, Media Session
XPathResult.UNORDERED_NODE_ITERATOR_TYPE (WebIDL constant) §: Defined in DOM
XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE (WebIDL constant) §: Defined in DOM
"unorm10-10-10-2" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"unorm16x2" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"unorm16x4" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"unorm8x2" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"unorm8x4" (value for GPUVertexFormat WebIDL enumeration) §: Defined in WebGPU
"unpower" (value for SmartCardDisposition WebIDL enumeration) §: Defined in Web Smart Card API
SmartCardReaderStateFlagsIn.unpowered (WebIDL dictionary member) §: Defined in Web Smart Card API
SmartCardReaderStateFlagsOut.unpowered (WebIDL dictionary member) §: Defined in Web Smart Card API
"unpowered-card" (value for SmartCardResponseCode WebIDL enumeration) §: Defined in Web Smart Card API
ServiceWorkerRegistration.unregister() (WebIDL operation) §: Defined in Service Workers; Referenced in Prerendering Revamped, Clear Site Data
PeriodicSyncManager.unregister(tag) (WebIDL operation) §: Defined in Web Periodic Background Synchronization
FinalizationRegistry.unregister(unregisterToken) (WebIDL operation) §: Defined in ECMAScript
unregistered (concept for service worker registration ) §: Defined in Service Workers; Referenced in Web Periodic Background Synchronization
NavigatorContentUtils.unregisterProtocolHandler(scheme, url) (WebIDL operation) §: Defined in HTML; Referenced in Prerendering Revamped
unresolved reference (concept) §: Defined in SVG 2
"unresponsive-card" (value for SmartCardResponseCode WebIDL enumeration) §: Defined in Web Smart Card API
unrestricted double (WebIDL interface) §: Defined in Web IDL; Referenced in DOM, HTML, Streams, Network Information API, Protected Audience, Battery Status API, CSS Painting API 1, CSS View Transitions 1, CSSOM View, Encrypted Media Extensions, Geolocation Sensor, Geometry Interfaces 1, Indexed DB 3.0, Media Source Extensions™, Media Session, Resize Observer, Web Animations, Web Animations 2, WebGPU, WebRTC 1.0, WebTransport, WebVTT: The Web Video Text Tracks Format; see also WebIDLPedia
unrestricted float (WebIDL interface) §: Defined in Web IDL; Referenced in WebCodecs, WebGPU; see also WebIDLPedia
unsafe (CSS value for <overflow-position> ) §: Defined in CSS Box Alignment 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
unsafe current time (concept for wall clock ) §: Defined in High Resolution Time; Referenced in Topics API, Navigational-Tracking Mitigations
unsafe current time (concept for monotonic clock ) §: Defined in High Resolution Time; Referenced in Generic Sensor API
unsafe response (concept) §: Defined in HTML; Referenced in Service Workers
unsafe shared current time (concept) §: Defined in High Resolution Time; Referenced in Fetch, HTML, Long Animation Frames API, Generic Sensor API, Service Workers
'unsafe-allow-redirects' (grammar) §: Defined in Content Security Policy 3
'unsafe-eval' (grammar) §: Defined in Content Security Policy 3; Referenced in Trusted Types
'unsafe-hashes' (grammar) §: Defined in Content Security Policy 3
'unsafe-inline' (grammar) §: Defined in Content Security Policy 3; Referenced in Content Security Policy: Embedded Enforcement
unsafe-none (concept for embedder policy value ) §: Defined in HTML; Referenced in Fetch
unsafe-request flag (concept for request ) §: Defined in Fetch; Referenced in HTML, Attribution Reporting, XMLHttpRequest
unsafe-url (CSS value for <request-url-modifier> ) §: Defined in CSS Values 5
"unsafe-url" (value for ReferrerPolicy WebIDL enumeration) §: Defined in Referrer Policy
unsafe-url (concept) §: Defined in Referrer Policy; Referenced in HTML
ClipboardUnsanitizedFormats.unsanitized (WebIDL dictionary member) §: Defined in Clipboard API and events
unscaled (concept) §: Defined in CSS Viewport 1; Referenced in CSSOM View
Unscopable (WebIDL extended attribute) §: Defined in Web IDL; Referenced in DOM, Fullscreen API
@@unscopables (WebIDL constant) §: Defined in ECMAScript; Referenced in HTML, ECMAScript Internationalization API, 2022, Intl.DurationFormat, Iterator Helpers, ShadowRealm API, Source Phase Imports, Temporal, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, Web IDL, WebAssembly JavaScript Interface
Symbol.unscopables (WebIDL attribute) §: Defined in ECMAScript
unsecured data document (concept) §: Defined in Verifiable Credential Data Integrity 1.0
XMLHttpRequest.UNSENT (WebIDL constant) §: Defined in XMLHttpRequest
unset (CSS value for all ) §: Defined in CSS Cascading 3 , CSS Cascading 4 , CSS Cascading 5; Referenced in CSS Variables 2, CSS Snapshot 2022, CSS Snapshot 2023, CSS Cascading 6, CSS Properties and Values API 1, CSS Pseudo-Elements 4, CSS Values 3, CSS Values 4, CSS Variables 1
unshaped edge (concept) §: Defined in CSS Box Model 4
Array.unshift(...items) (WebIDL operation) §: Defined in ECMAScript
unsigned long (WebIDL interface) §: Defined in Web IDL; Referenced in DOM, Font Metrics API 1, Federated Credential Management API, HTML, WebXR Raw Camera Access, Notifications API, URL, Gamepad Extensions, Media Playback Quality, Media Capture Automation, WebAssembly JavaScript Interface: Content Security Policy, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, WebAssembly JavaScript Interface: Type Reflection, Web Bluetooth, Direct Sockets API, Element Timing API, Fenced Frame, JS Self-Profiling API, Prerendering Revamped, Web Serial API, Shared Storage API, Protected Audience, HTMLVideoElement.requestVideoFrameCallback(), Web Smart Card API, WebHID API, WebUSB API, Compute Pressure 1, Content Security Policy 3, CSS Animations 1, CSS Font Loading 3, CSS Fonts 4, CSS Typed OM 1, CSSOM, CSSOM View, EditContext API, Encrypted Media Extensions, File API, Gamepad, Geolocation API, Geometry Interfaces 1, Indexed DB 3.0, Largest Contentful Paint, Media Capabilities, Media Source Extensions™, Media Capture and Streams, MediaStream Recording, requestIdleCallback() Cooperative Scheduling of Background Tasks, Resource Timing, Screen Capture, Secure Payment Confirmation, Selection API, Touch Events, UI Events, Vibration API, WebAssembly JavaScript Interface, Web Animations 2, Web Audio API, Web Authentication, FLAC WebCodecs Registration, Opus WebCodecs Registration, WebCodecs, Web Cryptography API, WebGPU, Web Neural Network API, WebRTC Encoded Transform, WebRTC Statistics, WebRTC 1.0, WebTransport, WebVTT: The Web Video Text Tracks Format, WebXR Depth Sensing, WebXR Hand Input 1, WebXR Device API, WebXR Layers API 1, XMLHttpRequest; see also WebIDLPedia
unsigned long long (WebIDL interface) §: Defined in Web IDL; Referenced in DOM, Encoding, File System, Topics API, Storage, Streams, WebSockets, Digital Goods API, Document Picture-in-Picture, Idle Detection API, JS Self-Profiling API, Network Information API, Prioritized Task Scheduling, Storage Buckets API, Protected Audience, Badging API, Event Timing API, File API, Gamepad, High Resolution Time, Indexed DB 3.0, Media Capabilities, Performance Timeline, Resource Timing, Web Audio API, Opus WebCodecs Registration, WebCodecs, WebGPU, WebRTC Encoded Transform, WebRTC Statistics, WebRTC 1.0, WebTransport, XMLHttpRequest; see also WebIDLPedia
unsigned short (WebIDL interface) §: Defined in Web IDL; Referenced in DOM, CSS View Transitions 2, Fetch, Web Bluetooth, Web Bluetooth Scanning, WebSockets, Direct Sockets API, Web Serial API, Accelerated Shape Detection in Images, Protected Audience, WebHID API, WebUSB API, Content Security Policy 3, CSS Animations 1, CSS Conditional 3, CSS Counter Styles 3, CSS Fonts 4, CSSOM, File API, Filter Effects 1, Geolocation API, MediaStreamTrack Insertable Media Processing using Streams, Resource Timing, Screen Orientation, UI Events, AV1 WebCodecs Registration, H.264, H.265, VP9 WebCodecs Registration, Web Cryptography API, WebGPU, WebRTC Encoded Transform, WebRTC Statistics, WebRTC 1.0, WebTransport, XMLHttpRequest; see also WebIDLPedia
"unspecified" (value for PresentationStyle WebIDL enumeration) §: Defined in Clipboard API and events
unstable (concept) §: Defined in Layout Instability
unstable node set (concept) §: Defined in Layout Instability
unstable-candidate (concept) §: Defined in Layout Instability
CookieStoreManager.unsubscribe(subscriptions) (WebIDL operation) §: Defined in Cookie Store API
PushSubscription.unsubscribed() (WebIDL operation) §: Defined in Push API
"unsupported-card" (value for SmartCardResponseCode WebIDL enumeration) §: Defined in Web Smart Card API
"unsupported-feature" (value for SmartCardResponseCode WebIDL enumeration) §: Defined in Web Smart Card API
SVGSVGElement.unsuspendRedraw() (WebIDL operation) §: Defined in SVG 2
SVGSVGElement.unsuspendRedrawAll() (WebIDL operation) §: Defined in SVG 2
untagged image (concept) §: Defined in CSS Color 4
untagged video (concept) §: Defined in CSS Color 4
until-found (value for hidden attribute of html-global ) §: Defined in HTML
unusable (concept for Body ) §: Defined in Fetch; Referenced in Service Workers
"unwrapKey" (value for KeyUsage WebIDL enumeration) §: Defined in Web Cryptography API
SubtleCrypto.unwrapKey() (WebIDL operation) §: Defined in Web Cryptography API
"up" (value for SpatialNavigationDirection WebIDL enumeration) §: Defined in CSS Spatial Navigation 1
up (CSS value for block-step-align ) §: Defined in CSS Rhythmic Sizing
up (CSS value for <rounding-strategy> ) §: Defined in CSS Values 4
"up" (value for ScrollSetting WebIDL enumeration) §: Defined in WebVTT: The Web Video Text Tracks Format
"upc_a" (value for BarcodeFormat WebIDL enumeration) §: Defined in Accelerated Shape Detection in Images
"upc_e" (value for BarcodeFormat WebIDL enumeration) §: Defined in Accelerated Shape Detection in Images
update (event) §: Defined in Media Source Extensions™
update (CSS descriptor for @media ) §: Defined in Media Queries 4 , Media Queries 5; Related terms: CSS value fast, CSS value none, CSS value slow
update (event for AudioRenderCapacity ) §: Defined in Web Audio API
StartViewTransitionOptions.update (WebIDL dictionary member) §: Defined in CSS View Transitions 2
update a style block (concept) §: Defined in HTML; Referenced in Content Security Policy 3
update animations and send events (concept) §: Defined in Web Animations; Referenced in HTML, Scroll-driven Animations, Web Animations 2
update document frozenness steps (concept) §: Defined in Page Lifecycle
Update latest reading (concept) §: Defined in Generic Sensor API; Referenced in Ambient Light Sensor
Update Requests (concept) §: Defined in W3C Process Document
update snapchanged targets (concept for Document ) §: Defined in CSS Scroll Snap 2; Referenced in CSSOM View
update snapchanging targets (concept for Document ) §: Defined in CSS Scroll Snap 2; Referenced in CSSOM View
update style attribute for (concept) §: Defined in CSSOM; Referenced in Web Animations
update the canvas size (algorithm) §: Defined in WebGPU
update the data max message size (algorithm) §: Defined in WebRTC 1.0
update the negotiation-needed flag (algorithm) §: Defined in WebRTC 1.0
update the rendering (concept) §: Defined in HTML; Referenced in Element Timing API, Layout Instability, Page Lifecycle, HTMLVideoElement.requestVideoFrameCallback(), CSS Containment 2, EditContext API, Event Timing API, Long Tasks API, Paint Timing
update via cache mode (concept for service worker registration ) §: Defined in Service Workers
MediaKeySession.update() (WebIDL operation) §: Defined in Encrypted Media Extensions
ServiceWorkerRegistration.update() (WebIDL operation) §: Defined in Service Workers; Referenced in Prerendering Revamped
IDBCursor.update(value) (WebIDL operation) §: Defined in Indexed DB 3.0
Navigator.updateAdInterestGroups() (WebIDL operation) §: Defined in Protected Audience
UpdateCallback (WebIDL callback) §: Defined in CSS View Transitions 1; Referenced in CSS View Transitions 2
ViewTransition.updateCallbackDone (WebIDL attribute) §: Defined in CSS View Transitions 1; Referenced in CSS View Transitions 2
EditContext.updateCharacterBounds() (WebIDL operation) §: Defined in EditContext API
EditContext.updateControlBounds() (WebIDL operation) §: Defined in EditContext API
Navigation.updateCurrentEntry(options) (WebIDL operation) §: Defined in HTML
UpdateEmpty (algorithm) §: Defined in ECMAScript; Referenced in ECMAScript Async Explicit Resource Management, ECMAScript Explicit Resource Management
updateend (event) §: Defined in Media Source Extensions™
updatefound (event for ServiceWorkerRegistration ) §: Defined in Service Workers
InkPresenter.updateInkTrailStartPoint(event, style) (WebIDL operation) §: Defined in Ink API
AudioRenderCapacityOptions.updateInterval (WebIDL dictionary member) §: Defined in Web Audio API
Animation.updatePlaybackRate(playbackRate) (WebIDL operation) §: Defined in Web Animations
TextUpdateEvent.updateRangeEnd (WebIDL attribute) §: Defined in EditContext API
TextUpdateEventInit.updateRangeEnd (WebIDL dictionary member) §: Defined in EditContext API
TextUpdateEvent.updateRangeStart (WebIDL attribute) §: Defined in EditContext API
TextUpdateEventInit.updateRangeStart (WebIDL dictionary member) §: Defined in EditContext API
XRSession.updateRenderState(state) (WebIDL operation) §: Defined in WebXR Device API; Referenced in WebXR Layers API 1
EditContext.updateSelection() (WebIDL operation) §: Defined in EditContext API
EditContext.updateSelectionBounds() (WebIDL operation) §: Defined in EditContext API
updatestart (event) §: Defined in Media Source Extensions™
XRSession.updateTargetFrameRate(rate) (WebIDL operation) §: Defined in WebXR Device API
EditContext.updateText() (WebIDL operation) §: Defined in EditContext API
AnimationEffect.updateTiming(timing) (WebIDL operation) §: Defined in Web Animations; Referenced in CSS Animation Worklet API, CSS Animations 2
BackgroundFetchUpdateUIEvent.updateUI(options) (WebIDL operation) §: Defined in Background Fetch
GenerateBidInterestGroup.updateURL (WebIDL dictionary member) §: Defined in Protected Audience
RegistrationOptions.updateViaCache (WebIDL dictionary member) §: Defined in Service Workers
ServiceWorkerRegistration.updateViaCache (WebIDL attribute) §: Defined in Service Workers
PaymentRequestUpdateEvent.updateWith() (WebIDL operation) §: Defined in Payment Request API 1.1
SourceBuffer.updating (WebIDL attribute) §: Defined in Media Source Extensions™
updating flag (concept for CSSStyleDeclaration ) §: Defined in CSSOM
updating the rendering of a WebGPU canvas (algorithm) §: Defined in WebGPU
Upgrade (CSS value for insecure requests policy ) §: Defined in Upgrade Insecure Requests
Upgrade a mixed content request to a potentially trustworthy URL, if appropriate (concept) §: Defined in Mixed Content; Referenced in Fetch
upgrade a request (concept) §: Defined in Upgrade Insecure Requests
upgrade an element (concept) §: Defined in HTML; Referenced in DOM
upgrade insecure navigations set (concept) §: Defined in Upgrade Insecure Requests
Upgrade request to a potentially trustworthy URL, if appropriate (concept) §: Defined in Upgrade Insecure Requests; Referenced in Fetch
upgrade-insecure-requests (concept) §: Defined in Upgrade Insecure Requests
Upgrade-Insecure-Requests HTTP request header field (concept) §: Defined in Upgrade Insecure Requests
CustomElementRegistry.upgrade(root) (WebIDL operation) §: Defined in HTML
upgradeable mixed content (concept) §: Defined in Mixed Content
upgradeneeded (event for IDBOpenDBRequest ) §: Defined in Indexed DB 3.0
XMLHttpRequest.upload (WebIDL attribute) §: Defined in XMLHttpRequest
BackgroundFetchRegistration.uploaded (WebIDL attribute) §: Defined in Background Fetch
BackgroundFetchRegistration.uploadTotal (WebIDL attribute) §: Defined in Background Fetch
upon fulfillment (concept) §: Defined in Web IDL; Referenced in HTML, Streams, WebAssembly JavaScript Interface: Content Security Policy, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, WebAssembly JavaScript Interface: Type Reflection, Web Bluetooth, Shared Storage API, Protected Audience, WebUSB API, Media Capture and Streams, Payment Handler API, Payment Request API 1.1, Service Workers, WebAssembly JavaScript Interface, WebAssembly Web API, WebTransport
upon rejection (concept) §: Defined in Web IDL; Referenced in HTML, Streams, WebAssembly JavaScript Interface: Content Security Policy, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, WebAssembly JavaScript Interface: Type Reflection, Shared Storage API, Protected Audience, Media Capture and Streams, Payment Handler API, Payment Request API 1.1, Service Workers, WebAssembly JavaScript Interface, WebAssembly Web API
CSSMathClamp.upper (WebIDL attribute) §: Defined in CSS Typed OM 1
IDBKeyRange.upper (WebIDL attribute) §: Defined in Indexed DB 3.0
MLTriangularOptions.upper (WebIDL dictionary member) §: Defined in Web Neural Network API
upper-alpha (CSS value for <counter-style-name> ) §: Defined in CSS Counter Styles 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Speech 1
upper-alpha (CSS value for list-style-type ) §: Defined in CSS 2.2
upper-armenian (CSS value for <counter-style-name> ) §: Defined in CSS Counter Styles 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
upper-latin (CSS value for <counter-style-name> ) §: Defined in CSS Counter Styles 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Speech 1
upper-latin (CSS value) §: Defined in CSS 2.1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
upper-latin (CSS value for list-style-type ) §: Defined in CSS 2.2
upper-roman (CSS value for <counter-style-name> ) §: Defined in CSS Counter Styles 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Speech 1
upper-roman (CSS value) §: Defined in CSS 2.1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
upper-roman (CSS value for list-style-type ) §: Defined in CSS 2.2
IDBKeyRange.upperBound(upper, open) (WebIDL operation) §: Defined in Indexed DB 3.0
uppercase (CSS value for text-transform ) §: Defined in CSS Text 3 , CSS Text 4 , CSS 2.2; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
uppercase letter (concept) §: Defined in CSS Syntax 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
IDBKeyRange.upperOpen (WebIDL attribute) §: Defined in Indexed DB 3.0
XREquirectLayer.upperVerticalAngle (WebIDL attribute) §: Defined in WebXR Layers API 1
XREquirectLayerInit.upperVerticalAngle (WebIDL dictionary member) §: Defined in WebXR Layers API 1
XRMediaEquirectLayerInit.upperVerticalAngle (WebIDL dictionary member) §: Defined in WebXR Layers API 1
upright (CSS value for page-orientation ) §: Defined in CSS Paged Media 3
upright (CSS value for text-orientation ) §: Defined in CSS Writing Modes 3 , CSS Writing Modes 4; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Inline Layout 3, CSS Text 3, CSS Text 4, CSS Values 3, CSS Values 4
AudioListener.upX (WebIDL attribute) §: Defined in Web Audio API
AudioListener.upY (WebIDL attribute) §: Defined in Web Audio API
AudioListener.upZ (WebIDL attribute) §: Defined in Web Audio API
URDNA2015 (concept) §: Defined in RDF Dataset Canonicalization
URGNA2012 (concept) §: Defined in RDF Dataset Canonicalization
<uri> (CSS type) §: Defined in CSS 2.1 , CSS 2.2; Referenced in CSS Typed OM 2, CSS Round Display 1, CSS Speech 1
<uri> (CSS value for content ) §: Defined in CSS 2.2
<uri> (CSS value for background-image ) §: Defined in CSS 2.2
RTCRtpHeaderExtensionCapability.uri (WebIDL dictionary member) §: Defined in WebRTC 1.0
RTCRtpHeaderExtensionParameters.uri (WebIDL dictionary member) §: Defined in WebRTC 1.0
URIError (exception) §: Defined in ECMAScript
URIError (exception) §: Defined in Web IDL
%URIError% (exception) §: Defined in ECMAScript; Referenced in ECMAScript Async Explicit Resource Management, ECMAScript Explicit Resource Management, Source Phase Imports
URL (concept for Document ) §: Defined in DOM; Referenced in HTML, Topics API, WebDriver BiDi, Background Fetch, Document Picture-in-Picture, Prefetch, Portals, URL Fragment Text Directives, Web Application Manifest, CSSOM, Mixed Content, Publication Manifest, Referrer Policy, XMLHttpRequest
URL (concept for request ) §: Defined in Fetch; Referenced in Federated Credential Management API, HTML, Topics API, requestStorageAccessFor API, Source Map, WebDriver BiDi, WebSockets, Attribution Reporting, Background Fetch, Content Index, Fenced Frame, Prefetch, Speculation Rules, Portals, Shared Storage API, Private State Token API, Protected Audience, Loading Signed Exchanges, Beacon, Content Security Policy 3, CSS Values 4, CSSOM, Fetch Metadata, Image Resource, Mixed Content, Payment Method Manifest, Service Workers, Trusted Types, Upgrade Insecure Requests, WebTransport, XMLHttpRequest
URL (concept for response ) §: Defined in Fetch; Referenced in Federated Credential Management API, HTML, Network Reporting API, WebDriver BiDi, Attribution Reporting, Scripting Policy, Fenced Frame, Prefetch, Speculation Rules, Loading Signed Exchanges, Clear Site Data, Content Security Policy: Embedded Enforcement, Content Security Policy 3, CSS Cascading 4, CSS Cascading 5, Mixed Content, Payment Method Manifest, Reporting API, XMLHttpRequest
URL (concept) §: Defined in URL; Referenced in DOM, Federated Credential Management API, Fetch, HTML, Navigational-Tracking Mitigations, Source Map, URL Pattern, Long Animation Frames API, Web Share Target API, WebDriver BiDi, WebSockets, Iframe credentialless, Attribution Reporting, Content Index, Scripting Policy, Fenced Frame, Manifest Incubations, No-Vary-Search, Prefetch, Prerendering Revamped, Speculation Rules, Portals, URL Fragment Text Directives, Shared Storage API, Protected Audience, Web App Launch Handler API, Loading Signed Exchanges, Web Application Manifest, Content Security Policy 3, CSS Syntax 3, CSS Values 4, CSSOM, EPUB 3.3, File API, Image Resource, MiniApp Manifest, MiniApp Packaging, Network Error Logging, Payment Method Identifiers, Payment Method Manifest, Presentation API, Publication Manifest, Push API, Referrer Policy, Reporting API, Secure Contexts, Service Workers, Upgrade Insecure Requests, Web Share API, WebDriver, WebTransport, XMLHttpRequest
URL (WebIDL interface) §: Defined in URL; Referenced in URL Pattern, A Well-Known URL for Passkey Endpoints, Get Installed Related Apps API, WebUSB API, A Well-Known URL for Changing Passwords, Content Security Policy 3, File API, Media Source Extensions™, Remote Playback API, Web Share API; see also WebIDLPedia
URL (concept for prefetch record ) §: Defined in Prefetch
Document.URL (WebIDL attribute) §: Defined in DOM
<url> (CSS value for mask-image ) §: Defined in CSS Masking 1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
<url> (CSS type) §: Defined in CSS Values 3 , CSS Values 4; Referenced in CSS Shapes 2, CSS Values 5, CSS Cascading 3, CSS Cascading 4, CSS Cascading 5, CSS Color 5, CSS Generated Content 3, CSS Fonts 4, CSS Fonts 5, CSS Images 3, CSS Namespaces 3, CSS Properties and Values API 1, CSS User Interface 4, CSSOM, Motion Path 1; Related terms: concept local url flag
<url> (CSS type for filter ) §: Defined in Filter Effects 1
url (value for type attribute of input element ) §: Defined in HTML
url (value for autocomplete attribute of button element, autocomplete attribute of fieldset element, autocomplete attribute of input element, autocomplete attribute of object element, autocomplete attribute of output element, autocomplete attribute of select element, autocomplete attribute of textarea element ) §: Defined in HTML
url (value for inputmode attribute of html-global ) §: Defined in HTML
url (concept for WorkerGlobalScope ) §: Defined in HTML; Referenced in Service Workers
url (concept for basic URL parser ) §: Defined in URL; Referenced in HTML, URL Pattern
url (concept for WebDriver navigation status ) §: Defined in WebDriver BiDi; Referenced in HTML
url (concept for violation ) §: Defined in Content Security Policy 3
url (concept for report ) §: Defined in Reporting API; Referenced in Network Reporting API
URL (state of markup element for input ) §: Defined in HTML
AdRender.url (WebIDL dictionary member) §: Defined in Protected Audience
Client.url (WebIDL attribute) §: Defined in Service Workers
ContentDescription.url (WebIDL dictionary member) §: Defined in Content Index
CookieStoreGetOptions.url (WebIDL dictionary member) §: Defined in Cookie Store API
endpoint.url (WebIDL attribute) §: Defined in Reporting API; Referenced in Network Reporting API
EventSource.url (WebIDL attribute) §: Defined in HTML
IdentityProviderIcon.url (WebIDL dictionary member) §: Defined in Federated Credential Management API
LargestContentfulPaint.url (WebIDL attribute) §: Defined in Largest Contentful Paint
MemoryAttribution.url (WebIDL dictionary member) §: Defined in Measure Memory API
NavigationDestination.url (WebIDL attribute) §: Defined in HTML
NavigationHistoryEntry.url (WebIDL attribute) §: Defined in HTML
NotRestoredReasons.url (WebIDL attribute) §: Defined in HTML
PerformanceElementTiming.url (WebIDL attribute) §: Defined in Element Timing API
PresentationConnection.url (WebIDL attribute) §: Defined in Presentation API
RelatedApplication.url (WebIDL dictionary member) §: Defined in Get Installed Related Apps API
Report.url (WebIDL attribute) §: Defined in Reporting API
Request.url (WebIDL attribute) §: Defined in Fetch; Referenced in Loading Signed Exchanges, Largest Contentful Paint
Response.url (WebIDL attribute) §: Defined in Fetch
RTCIceCandidate.url (WebIDL attribute) §: Defined in WebRTC 1.0
RTCIceCandidateStats.url (WebIDL dictionary member) §: Defined in WebRTC Statistics
RTCPeerConnectionIceErrorEvent.url (WebIDL attribute) §: Defined in WebRTC 1.0
RTCPeerConnectionIceErrorEventInit.url (WebIDL dictionary member) §: Defined in WebRTC 1.0
RTCPeerConnectionIceEvent.url (WebIDL attribute) §: Defined in WebRTC 1.0
RTCPeerConnectionIceEventInit.url (WebIDL dictionary member) §: Defined in WebRTC 1.0
ShareData.url (WebIDL dictionary member) §: Defined in Web Share API
SharedStorageUrlWithMetadata.url (WebIDL dictionary member) §: Defined in Shared Storage API
StorageEvent.url (WebIDL attribute) §: Defined in HTML
WebSocket.url (WebIDL attribute) §: Defined in WebSockets
URL code point (concept) §: Defined in URL; Referenced in URL Fragment Text Directives
URL list (concept for request ) §: Defined in Fetch; Referenced in HTML, Prefetch, Fetch Metadata
URL list (concept for response ) §: Defined in Fetch; Referenced in HTML, Navigational-Tracking Mitigations, Loading Signed Exchanges, Mixed Content
URL object (concept for URLSearchParams ) §: Defined in URL
URL parser (concept) §: Defined in URL; Referenced in Federated Credential Management API, Fetch, HTML, Notifications API, requestStorageAccessFor API, The Storage Access API, URL Pattern, Network Reporting API, Web NFC API, Web Share Target API, WebDriver BiDi, WebSockets, Attribution Reporting, Content Index, Element Timing API, Fenced Frame, Manifest Incubations, Shared Storage API, Private State Token API, Protected Audience, Loading Signed Exchanges, Web Application Manifest, Beacon, Content Security Policy 3, CSS Cascading 4, CSS Values 4, CSSOM, EPUB 3.3, EPUB Reading Systems 3.3, File API, Image Resource, Media Session, MiniApp Manifest, MiniApp Packaging, Payment Handler API, Permissions Policy, Publication Manifest, Reporting API, Secure Payment Confirmation, Service Workers, SVG 2, Trusted Types, Web Share API, WebRTC 1.0, WebTransport
URL path (concept) §: Defined in URL
URL path segment (concept) §: Defined in URL
URL path serializer (concept) §: Defined in URL; Referenced in HTML, URL Pattern, WebDriver BiDi
URL pattern (concept) §: Defined in URL Pattern; Referenced in Speculation Rules, Service Workers; Related terms: concept create, concept has regexp groups, concept match
URL reference (concept) §: Defined in SVG 2; Referenced in SVG Animations 2
URL reference with fragment identifier (concept) §: Defined in SVG 2
URL request modifier steps (concept) §: Defined in CSS Values 4; Referenced in CSS Values 5
URL serializer (concept) §: Defined in URL; Referenced in DOM, Fetch, HTML, Notifications API, URL Pattern, Web NFC API, Web Share Target API, WebDriver BiDi, WebSockets, Attribution Reporting, Shared Storage API, Protected Audience, Loading Signed Exchanges, Content Security Policy 3, CSSOM, EPUB 3.3, File API, Network Error Logging, Publication Manifest, Referrer Policy, Reporting API, Service Workers, Trusted Types, Web Share API, WebDriver, XMLHttpRequest; Related terms: concept exclude fragment
DOMException.URL_MISMATCH_ERR (WebIDL constant) §: Defined in Web IDL
URL-based payment method identifier (concept) §: Defined in Payment Method Identifiers; Referenced in Payment Method Manifest
URL-fragment string (concept) §: Defined in URL; Referenced in EPUB 3.3, EPUB Reading Systems 3.3
<url-modifier> (CSS type) §: Defined in CSS Values 3 , CSS Values 4; Referenced in CSS Linked Parameters, CSS Values 5
URL-path-segment string (concept) §: Defined in URL; Referenced in MiniApp Packaging
URL-port string (concept) §: Defined in URL
URL-query string (concept) §: Defined in URL
URL-scheme string (concept) §: Defined in URL; Referenced in EPUB Reading Systems 3.3
<url-set> (CSS type for cursor ) §: Defined in CSS User Interface 4
<url-token> (CSS type) §: Defined in CSS Syntax 3; Referenced in CSS Values 3, CSS Values 4
url() (CSS function) §: Defined in CSS Values 3 , CSS Values 4; Referenced in CSS Linked Parameters, CSS Cascading 3, CSS Cascading 4, CSS Cascading 5, CSS Color Adjustment 1, CSS Images 3, CSS Syntax 3, CSS Typed OM 1; Related terms: concept local url flag
new URL(url, base) (WebIDL constructor) §: Defined in URL; Referenced in Private Click Measurement
urlencoded parser (concept) §: Defined in URL; Referenced in Fetch, No-Vary-Search
urlencoded serializer (concept) §: Defined in URL; Referenced in Federated Credential Management API, Fetch, HTML, Web Share Target API, Protected Audience
URLMismatchError (exception) §: Defined in Web IDL
URLPattern (WebIDL interface) §: Defined in URL Pattern; Related terms: URLPattern.hash, URLPattern.hasRegExpGroups, URLPattern.hostname, URLPattern.password, URLPattern.pathname, URLPattern.port, URLPattern.protocol, URLPattern.search, URLPattern.username, new URLPattern(input, baseURL, options), new URLPattern(input, options), URLPattern.exec(input, baseURL), URLPattern.test(input, baseURL); see also WebIDLPedia
RouterCondition.urlPattern (WebIDL dictionary member) §: Defined in Service Workers
new URLPattern(input, baseURL, options) (WebIDL constructor) §: Defined in URL Pattern
new URLPattern(input, options) (WebIDL constructor) §: Defined in URL Pattern
URLPatternCompatible (WebIDL type alias) §: Defined in URL Pattern; Referenced in Service Workers; see also WebIDLPedia
URLPatternComponentResult (WebIDL dictionary) §: Defined in URL Pattern; Related terms: URLPatternComponentResult.groups, URLPatternComponentResult.input; see also WebIDLPedia
URLPatternInit (WebIDL dictionary) §: Defined in URL Pattern; Related terms: URLPatternInit.baseURL, URLPatternInit.hash, URLPatternInit.hostname, URLPatternInit.password, URLPatternInit.pathname, URLPatternInit.port, URLPatternInit.protocol, URLPatternInit.search, URLPatternInit.username; see also WebIDLPedia
URLPatternInput (WebIDL type alias) §: Defined in URL Pattern; see also WebIDLPedia
URLPatternOptions (WebIDL dictionary) §: Defined in URL Pattern; Related terms: URLPatternOptions.ignoreCase; see also WebIDLPedia
URLPatternResult (WebIDL dictionary) §: Defined in URL Pattern; Related terms: URLPatternResult.hash, URLPatternResult.hostname, URLPatternResult.inputs, URLPatternResult.password, URLPatternResult.pathname, URLPatternResult.port, URLPatternResult.protocol, URLPatternResult.search, URLPatternResult.username; see also WebIDLPedia
FontFace.[[Urls]] (internal slot) §: Defined in CSS Font Loading 3
RTCIceServer.urls (WebIDL dictionary member) §: Defined in WebRTC 1.0
URLSearchParams (WebIDL interface) §: Defined in URL; Referenced in Fetch; Related terms: concept list, concept URL object, URLSearchParams.size, new URLSearchParams(init), URLSearchParams.append(name, value), URLSearchParams.delete(name, value), URLSearchParams.get(name), URLSearchParams.getAll(name), URLSearchParams.has(name, value), URLSearchParams.set(name, value), URLSearchParams.sort(); see also WebIDLPedia
new URLSearchParams(init) (WebIDL constructor) §: Defined in URL
urn (markup attribute for a ) §: Defined in HTML
urn (markup attribute for link ) §: Defined in HTML
UrnOrConfig (WebIDL type alias) §: Defined in Fenced Frame; see also WebIDLPedia
"usable" (value for MediaKeyStatus WebIDL enumeration) §: Defined in Encrypted Media Extensions
"usable-in-future" (value for MediaKeyStatus WebIDL enumeration) §: Defined in Encrypted Media Extensions
FontFacePalette.usableWithDarkBackground (WebIDL attribute) §: Defined in CSS Font Loading 3
FontFacePalette.usableWithLightBackground (WebIDL attribute) §: Defined in CSS Font Loading 3
GPUBuffer.usage (WebIDL attribute) §: Defined in WebGPU
GPUBufferDescriptor.usage (WebIDL dictionary member) §: Defined in WebGPU
GPUCanvasConfiguration.usage (WebIDL dictionary member) §: Defined in WebGPU
GPUTexture.usage (WebIDL attribute) §: Defined in WebGPU
GPUTextureDescriptor.usage (WebIDL dictionary member) §: Defined in WebGPU
HIDCollectionInfo.usage (WebIDL dictionary member) §: Defined in WebHID API
HIDDeviceFilter.usage (WebIDL dictionary member) §: Defined in WebHID API
StorageEstimate.usage (WebIDL dictionary member) §: Defined in Storage; Referenced in Storage Buckets API
HIDReportItem.usageMaximum (WebIDL dictionary member) §: Defined in WebHID API
HIDReportItem.usageMinimum (WebIDL dictionary member) §: Defined in WebHID API
HIDCollectionInfo.usagePage (WebIDL dictionary member) §: Defined in WebHID API
HIDDeviceFilter.usagePage (WebIDL dictionary member) §: Defined in WebHID API
XRDepthStateInit.usagePreference (WebIDL dictionary member) §: Defined in WebXR Depth Sensing
CryptoKey.usages (WebIDL attribute) §: Defined in Web Cryptography API
HIDReportItem.usages (WebIDL dictionary member) §: Defined in WebHID API
USB (WebIDL interface) §: Defined in WebUSB API; Related terms: USB.onconnect, USB.ondisconnect, USB.getDevices(), USB.requestDevice(options); see also WebIDLPedia
"usb" (value for PermissionName WebIDL enumeration) §: Defined in WebUSB API
"usb" (value for AuthenticatorTransport WebIDL enumeration) §: Defined in Web Authentication
Navigator.usb (WebIDL attribute) §: Defined in WebUSB API
WorkerNavigator.usb (WebIDL attribute) §: Defined in WebUSB API
USBAlternateInterface (WebIDL interface) §: Defined in WebUSB API; Related terms: undefined[[alternateSetting]], undefined[[endpoints]], USBAlternateInterface.[[interface]], USBAlternateInterface.interfaceClass, USBAlternateInterface.interfaceName, USBAlternateInterface.interfaceProtocol, USBAlternateInterface.interfaceSubclass, new USBAlternateInterface(deviceInterface, alternateSetting); see also WebIDLPedia
new USBAlternateInterface(deviceInterface, alternateSetting) (WebIDL constructor) §: Defined in WebUSB API
USBBlocklistEntry (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBBlocklistEntry.bcdDevice, USBBlocklistEntry.idProduct, USBBlocklistEntry.idVendor; see also WebIDLPedia
USBConfiguration (WebIDL interface) §: Defined in WebUSB API; Related terms: USBConfiguration.configurationName, undefined[[configurationValue]], USBConfiguration.[[device]], undefined[[interfaces]], new USBConfiguration(device, configurationValue); see also WebIDLPedia
new USBConfiguration(device, configurationValue) (WebIDL constructor) §: Defined in WebUSB API
USBConnectionEvent (WebIDL interface) §: Defined in WebUSB API; Related terms: USBConnectionEvent.device, new USBConnectionEvent(type, eventInitDict); see also WebIDLPedia
new USBConnectionEvent(type, eventInitDict) (WebIDL constructor) §: Defined in WebUSB API
USBConnectionEventInit (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBConnectionEventInit.device; see also WebIDLPedia
USBControlTransferParameters (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBControlTransferParameters.index, USBControlTransferParameters.recipient, USBControlTransferParameters.request, USBControlTransferParameters.requestType, USBControlTransferParameters.value; see also WebIDLPedia
USBDevice (WebIDL interface) §: Defined in WebUSB API; Related terms: USBDevice.[[claimedInterface]], USBDevice.configuration, undefined[[configurations]], USBDevice.[[configurationValue]], USBDevice.deviceClass, USBDevice.deviceProtocol, USBDevice.deviceSubclass, USBDevice.deviceVersionMajor, USBDevice.deviceVersionMinor, USBDevice.deviceVersionSubminor, USBDevice.manufacturerName, USBDevice.opened, USBDevice.productId, USBDevice.productName, USBDevice.[[selectedAlternateSetting]], USBDevice.serialNumber, USBDevice.usbVersionMajor, USBDevice.usbVersionMinor, USBDevice.usbVersionSubminor, USBDevice.vendorId, USBDevice.claimInterface(interfaceNumber), USBDevice.clearHalt(direction, endpointNumber), USBDevice.close(), USBDevice.controlTransferIn(setup, length), USBDevice.controlTransferOut(setup, data), USBDevice.forget(), USBDevice.isochronousTransferIn(endpointNumber, packetLengths), USBDevice.isochronousTransferOut(endpointNumber, data, packetLengths), USBDevice.open(), USBDevice.releaseInterface(interfaceNumber), USBDevice.reset(), USBDevice.selectAlternateInterface(interfaceNumber, alternateSetting), USBDevice.selectConfiguration(configurationValue), USBDevice.transferIn(endpointNumber, length), USBDevice.transferOut(endpointNumber, data); see also WebIDLPedia
USBDeviceFilter (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBDeviceFilter.classCode, USBDeviceFilter.productId, USBDeviceFilter.protocolCode, USBDeviceFilter.serialNumber, USBDeviceFilter.subclassCode, USBDeviceFilter.vendorId; see also WebIDLPedia
USBDeviceRequestOptions (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBDeviceRequestOptions.exclusionFilters, USBDeviceRequestOptions.filters; see also WebIDLPedia
USBDirection (WebIDL enumeration) §: Defined in WebUSB API; Related terms: value in, value out; see also WebIDLPedia
USBEndpoint (WebIDL interface) §: Defined in WebUSB API; Related terms: USBEndpoint.[[alternateInterface]], USBEndpoint.direction, USBEndpoint.[[endpointAddress]], USBEndpoint.endpointNumber, USBEndpoint.packetSize, USBEndpoint.type, new USBEndpoint(alternate, endpointNumber, direction); see also WebIDLPedia
new USBEndpoint(alternate, endpointNumber, direction) (WebIDL constructor) §: Defined in WebUSB API
USBEndpointType (WebIDL enumeration) §: Defined in WebUSB API; Related terms: value bulk, value interrupt, value isochronous; see also WebIDLPedia
USBInterface (WebIDL interface) §: Defined in WebUSB API; Related terms: USBInterface.alternate, undefined[[alternates]], USBInterface.claimed, USBInterface.[[configuration]], undefined[[interfaceNumber]], USBInterface.[[isProtectedClass]], new USBInterface(configuration, interfaceNumber); see also WebIDLPedia
new USBInterface(configuration, interfaceNumber) (WebIDL constructor) §: Defined in WebUSB API
USBInTransferResult (WebIDL interface) §: Defined in WebUSB API; Related terms: USBInTransferResult.data, USBInTransferResult.status, new USBInTransferResult(status, data); see also WebIDLPedia
new USBInTransferResult(status, data) (WebIDL constructor) §: Defined in WebUSB API
USBIsochronousInTransferPacket (WebIDL interface) §: Defined in WebUSB API; Related terms: USBIsochronousInTransferPacket.data, USBIsochronousInTransferPacket.status, new USBIsochronousInTransferPacket(status, data); see also WebIDLPedia
new USBIsochronousInTransferPacket(status, data) (WebIDL constructor) §: Defined in WebUSB API
USBIsochronousInTransferResult (WebIDL interface) §: Defined in WebUSB API; Related terms: USBIsochronousInTransferResult.data, USBIsochronousInTransferResult.packets, new USBIsochronousInTransferResult(packets, data); see also WebIDLPedia
new USBIsochronousInTransferResult(packets, data) (WebIDL constructor) §: Defined in WebUSB API
USBIsochronousOutTransferPacket (WebIDL interface) §: Defined in WebUSB API; Related terms: USBIsochronousOutTransferPacket.bytesWritten, USBIsochronousOutTransferPacket.status, new USBIsochronousOutTransferPacket(status, bytesWritten); see also WebIDLPedia
new USBIsochronousOutTransferPacket(status, bytesWritten) (WebIDL constructor) §: Defined in WebUSB API
USBIsochronousOutTransferResult (WebIDL interface) §: Defined in WebUSB API; Related terms: USBIsochronousOutTransferResult.packets, new USBIsochronousOutTransferResult(packets); see also WebIDLPedia
new USBIsochronousOutTransferResult(packets) (WebIDL constructor) §: Defined in WebUSB API
USBOutTransferResult (WebIDL interface) §: Defined in WebUSB API; Related terms: USBOutTransferResult.bytesWritten, USBOutTransferResult.status, new USBOutTransferResult(status, bytesWritten); see also WebIDLPedia
new USBOutTransferResult(status, bytesWritten) (WebIDL constructor) §: Defined in WebUSB API
USBPermissionDescriptor (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBPermissionDescriptor.exclusionFilters, USBPermissionDescriptor.filters; see also WebIDLPedia
USBPermissionResult (WebIDL interface) §: Defined in WebUSB API; Related terms: USBPermissionResult.devices; see also WebIDLPedia
USBPermissionStorage (WebIDL dictionary) §: Defined in WebUSB API; Related terms: USBPermissionStorage.allowedDevices; see also WebIDLPedia
SerialPortFilter.usbProductId (WebIDL dictionary member) §: Defined in Web Serial API
SerialPortInfo.usbProductId (WebIDL dictionary member) §: Defined in Web Serial API
USBRecipient (WebIDL enumeration) §: Defined in WebUSB API; Related terms: value device, value endpoint, value interface, value other; see also WebIDLPedia
USBRequestType (WebIDL enumeration) §: Defined in WebUSB API; Related terms: value class, value standard, value vendor; see also WebIDLPedia
USBTransferStatus (WebIDL enumeration) §: Defined in WebUSB API; Related terms: value babble, value ok, value stall; see also WebIDLPedia
SerialPortFilter.usbVendorId (WebIDL dictionary member) §: Defined in Web Serial API
SerialPortInfo.usbVendorId (WebIDL dictionary member) §: Defined in Web Serial API
USBDevice.usbVersionMajor (WebIDL attribute) §: Defined in WebUSB API
USBDevice.usbVersionMinor (WebIDL attribute) §: Defined in WebUSB API
USBDevice.usbVersionSubminor (WebIDL attribute) §: Defined in WebUSB API
"use" (value for IdentityCredentialRequestOptionsContext WebIDL enumeration) §: Defined in Federated Credential Management API
use (markup element) §: Defined in SVG 2; Referenced in CSS Display 4, Filter Effects 1; Related terms: markup attribute href, markup attribute requiredExtensions, markup attribute systemLanguage, markup attribute xlink:href, markup attribute xlink:title
JsonWebKey.use (WebIDL dictionary member) §: Defined in Web Cryptography API
use a negative sign (concept) §: Defined in CSS Counter Styles 3; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
Use Strict Directive (concept for ECMAScript ) §: Defined in ECMAScript
use-CORS-preflight flag (concept for request ) §: Defined in Fetch; Referenced in Private Network Access, XMLHttpRequest
use-credentials (CSS value for <request-url-modifier> ) §: Defined in CSS Values 5
use-credentials (value for crossorigin attribute of audio element, crossorigin attribute of img element, crossorigin attribute of link element, crossorigin attribute of script, crossorigin attribute of video element ) §: Defined in HTML
use-URL-credentials flag (concept for request ) §: Defined in Fetch; Referenced in HTML, Prefetch, CSS Values 4, Service Workers, XMLHttpRequest
used color (concept) §: Defined in CSS Color 4; Referenced in CSS Color 6
used color scheme (concept) §: Defined in CSS Color Adjustment 1; Referenced in Web Preferences API, CSS Color 5, Media Queries 5
used value (concept) §: Defined in CSS Cascading 3 , CSS Cascading 4 , CSS Cascading 5; Referenced in CSS Conditional Values 1, CSS Grid Layout 3, CSS Values 5, Quirks Mode, CSS Snapshot 2022, CSS Snapshot 2023, CSS Box Alignment 3, CSS Anchor Positioning, CSS Animations 2, CSS Backgrounds 3, CSS Color 4, CSS Color Adjustment 1, CSS Containment 2, CSS Flexbox 1, CSS Fonts 5, CSS Grid Layout 1, CSS Grid Layout 2, CSS Images 3, CSS Inline Layout 3, CSS Lists 3, CSS Logical Properties 1, CSS Overflow 4, CSS Positioned Layout 3, CSS Pseudo-Elements 4, CSS Text 4, CSS Transforms 1, CSS Transforms 2, CSS User Interface 4, CSS Values 3, CSS Values 4, CSS Writing Modes 3, CSS Writing Modes 4, CSSOM, Filter Effects 1, Paint Timing, Scroll-driven Animations
used value (concept) §: Defined in CSS 2.1
GPUBindGroup.[[usedResources]] (internal slot) §: Defined in WebGPU
OpusEncoderConfig.usedtx (WebIDL dictionary member) §: Defined in Opus WebCodecs Registration
OpusEncoderConfig.useinbandfec (WebIDL dictionary member) §: Defined in Opus WebCodecs Registration
HTMLImageElement.useMap (WebIDL attribute) §: Defined in HTML
HTMLInputElement.useMap (WebIDL attribute) §: Defined in HTML
HTMLObjectElement.useMap (WebIDL attribute) §: Defined in HTML
usemap (markup attribute for img ) §: Defined in HTML; Referenced in HTML Accessibility API Mappings 1.0
usemap (markup attribute for input ) §: Defined in HTML
usemap (markup attribute for object ) §: Defined in HTML
JsonLdOptions.useNativeTypes (WebIDL dictionary member) §: Defined in JSON-LD 1.1 Processing Algorithms and API
useParallelQueue (concept for fetch ) §: Defined in Fetch; Referenced in HTML, WebSockets, Fenced Frame, Prefetch, Protected Audience, XMLHttpRequest
User (concept) §: Defined in CSS Snapshot 2022 , CSS Snapshot 2023
User (concept) §: Defined in CSS 2.1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
"user" (value for VideoFacingModeEnum WebIDL enumeration) §: Defined in Media Capture and Streams
PublicKeyCredentialCreationOptions.user (WebIDL dictionary member) §: Defined in Web Authentication; Referenced in Secure Payment Confirmation
PublicKeyCredentialCreationOptionsJSON.user (WebIDL dictionary member) §: Defined in Web Authentication
user accepts the payment request algorithm (concept) §: Defined in Payment Request API 1.1
user activation (concept) §: Defined in HTML; Referenced in Web Bluetooth, Web Bluetooth Scanning, Attribution Reporting, Fenced Frame, Shared Storage API, Pointer Lock 2.0
user agent (concept) §: Defined in Infra; Referenced in Compatibility, CSS Positioned Layout 4, Federated Credential Management API, Topics API, Storage, MathML Accessibility API Mappings 1.0, Media Capture Automation, Client Hints Infrastructure, Digital Goods API, Digital Credentials, Idle Detection API, Manifest Incubations, Prerendering Revamped, Shared Storage API, Protected Audience, User-Agent Client Hints, Web Preferences API, Accessible Name and Description Computation 1.2, Web Application Manifest, Badging API, Core Accessibility API Mappings 1.2, Digital Publishing Accessibility API Mappings 1.1, Digital Publishing WAI-ARIA 1.1, Gamepad, Graphics Accessibility API Mappings, High Resolution Time, HTML Accessibility API Mappings 1.0, Input Events 2, Media Source Extensions™, Viewport Capture, Permissions, Picture-in-Picture, Screen Orientation, Scroll-driven Animations, Selection API, User Timing, WAI-ARIA, WAI-ARIA, Web Locks API, Web MIDI API
user agent (concept) §: Defined in CSS 2.1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
user agent (concept for report ) §: Defined in Reporting API
user context (concept) §: Defined in WebDriver BiDi; Referenced in Permissions; Related terms: concept user context id
user context id (concept for user context ) §: Defined in WebDriver BiDi
user coordinate system (concept) §: Defined in CSS Transforms 1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
user coordinate system (concept) §: Defined in SVG 2
user interaction task source (concept) §: Defined in HTML; Referenced in WebDriver BiDi, Content Index, Early detection of input events, Badging API, Device Posture API, Media Session, Payment Handler API, Payment Request API 1.1, Push API, Screen Orientation, Selection API, Service Workers, Web Share API
user mediated (concept) §: Defined in Credential Management 1; Referenced in WebOTP API, Web Authentication
user navigation involvement (concept) §: Defined in HTML; Referenced in CSS View Transitions 2, URL Fragment Text Directives; Related terms: concept activation, concept browser UI, concept none
user origin (concept) §: Defined in CSS Cascading 3 , CSS Cascading 4 , CSS Cascading 5; Referenced in CSS Snapshot 2022, CSS Snapshot 2023, CSS Anchor Positioning, CSS Cascading 6, CSS Lists 3, CSS Scrollbars Styling 1, CSS Text 4
user units (concept) §: Defined in SVG 2
user-activation (concept for request ) §: Defined in Fetch; Referenced in HTML, Prefetch, Fetch Metadata
user-agent origin (concept) §: Defined in CSS Cascading 3 , CSS Cascading 4 , CSS Cascading 5; Referenced in Web Preferences API, CSS Snapshot 2022, CSS Snapshot 2023, CSS Cascading 6, CSS Lists 3, CSS Overflow 4, CSS Scoping 1, CSS User Interface 4
"user-blocking" (value for TaskPriority WebIDL enumeration) §: Defined in Prioritized Task Scheduling
"user-callback" (value for ScriptInvokerType WebIDL enumeration) §: Defined in Long Animation Frames API
User-facing identifiers (concept) §: Defined in Internationalization Glossary
:user-invalid (CSS selector) §: Defined in Selectors 4
user-select (CSS property) §: Defined in CSS User Interface 4; Referenced in CSS Typed OM 1; Related terms: CSS value all, CSS value auto, CSS value contain, CSS value none, CSS value text
User-supplied value (concept) §: Defined in Internationalization Glossary
:user-valid (CSS selector) §: Defined in Selectors 4
"user-visible" (value for TaskPriority WebIDL enumeration) §: Defined in Prioritized Task Scheduling
UserActivation (WebIDL interface) §: Defined in HTML; Related terms: UserActivation.hasBeenActive, UserActivation.isActive; see also WebIDLPedia
Navigator.userActivation (WebIDL attribute) §: Defined in HTML
NavigatorID.userAgent (WebIDL attribute) §: Defined in HTML; Referenced in Measure Memory API, Reporting API, WebXR Device API
NavigatorUA.userAgentData (WebIDL attribute) §: Defined in User-Agent Client Hints
GenerateBidInterestGroup.userBiddingSignals (WebIDL dictionary member) §: Defined in Protected Audience
PromptResponseObject.userChoice (WebIDL dictionary member) §: Defined in Manifest Incubations
UserDataHandler (WebIDL interface) §: Defined in DOM; see also WebIDLPedia
JsonLdOptions.useRdfType (WebIDL dictionary member) §: Defined in JSON-LD 1.1 Processing Algorithms and API
AuthenticatorAssertionResponse.userHandle (WebIDL attribute) §: Defined in Web Authentication
AuthenticatorAssertionResponseJSON.userHandle (WebIDL dictionary member) §: Defined in Web Authentication
PaymentManager.userHint (WebIDL attribute) §: Defined in Payment Handler API
UserIdleState (WebIDL enumeration) §: Defined in Idle Detection API; Related terms: value active, value idle; see also WebIDLPedia
NavigateEvent.userInitiated (WebIDL attribute) §: Defined in HTML
NavigateEventInit.userInitiated (WebIDL dictionary member) §: Defined in HTML
username (value for autocomplete attribute of button element, autocomplete attribute of fieldset element, autocomplete attribute of input element, autocomplete attribute of object element, autocomplete attribute of output element, autocomplete attribute of select element, autocomplete attribute of textarea element ) §: Defined in HTML
username (concept for url ) §: Defined in URL; Referenced in Fetch, HTML, URL Pattern, No-Vary-Search, Content Security Policy 3, Payment Method Identifiers, Payment Method Manifest, Referrer Policy, Reporting API
username (concept for state of constructor string parser ) §: Defined in URL Pattern
HTMLHyperlinkElementUtils.username (WebIDL attribute) §: Defined in HTML
RTCIceServer.username (WebIDL dictionary member) §: Defined in WebRTC 1.0
username (WebIDL attribute for URL ) §: Defined in URL
URLPattern.username (WebIDL attribute) §: Defined in URL Pattern
URLPatternInit.username (WebIDL dictionary member) §: Defined in URL Pattern
URLPatternResult.username (WebIDL dictionary member) §: Defined in URL Pattern
RTCIceCandidate.usernameFragment (WebIDL attribute) §: Defined in WebRTC 1.0
RTCIceCandidateInit.usernameFragment (WebIDL dictionary member) §: Defined in WebRTC 1.0
RTCIceCandidateStats.usernameFragment (WebIDL dictionary member) §: Defined in WebRTC Statistics
RTCIceParameters.usernameFragment (WebIDL dictionary member) §: Defined in WebRTC 1.0
RTCIdentityProviderOptions.usernameHint (WebIDL dictionary member) §: Defined in Identity for WebRTC 1.0
userSpaceOnUse (CSS value for clipPathUnits ) §: Defined in CSS Masking 1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
userSpaceOnUse (CSS value for maskUnits ) §: Defined in CSS Masking 1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
userSpaceOnUse (CSS value for maskContentUnits ) §: Defined in CSS Masking 1; Referenced in CSS Snapshot 2022, CSS Snapshot 2023
userSpaceOnUse (value for filterUnits ) §: Defined in Filter Effects 1
userSpaceOnUse (value for primitiveUnits ) §: Defined in Filter Effects 1
IdleDetector.[[userState]] (internal slot) §
IdleDetector.[[userState]] (internal slot) §: Defined in Idle Detection API , Idle Detection API
AuthenticatorSelectionCriteria.userVerification (WebIDL dictionary member) §: Defined in Web Authentication; Referenced in CTAP, Secure Payment Confirmation
PublicKeyCredentialRequestOptions.userVerification (WebIDL dictionary member) §: Defined in Web Authentication; Referenced in CTAP, Secure Payment Confirmation
PublicKeyCredentialRequestOptionsJSON.userVerification (WebIDL dictionary member) §: Defined in Web Authentication
UserVerificationRequirement (WebIDL enumeration) §: Defined in Web Authentication; Related terms: value discouraged, value preferred, value required; see also WebIDLPedia
"userVerifyingPlatformAuthenticator" (value for ClientCapability WebIDL enumeration) §: Defined in Web Authentication
PushPermissionDescriptor.userVisibleOnly (WebIDL dictionary member) §: Defined in Push API
PushSubscriptionOptions.userVisibleOnly (WebIDL attribute) §: Defined in Push API
PushSubscriptionOptionsInit.userVisibleOnly (WebIDL dictionary member) §: Defined in Push API
XRWebGLBinding.usesDepthValues (WebIDL attribute) §: Defined in WebXR Layers API 1
USVString (WebIDL interface) §: Defined in Web IDL; Referenced in DOM, Encoding, Federated Credential Management API, Fetch, CTAP, File System, HTML, Notifications API, requestStorageAccessFor API, URL, URL Pattern, Web NFC API, WebAssembly JavaScript Interface: Content Security Policy, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, WebAssembly JavaScript Interface: Type Reflection, WebSockets, Attribution Reporting, Cookie Store API, File and Directory Entries API, Fenced Frame, File System Access, Local Font Access, Shared Storage API, Private State Token API, Protected Audience, Beacon, Credential Management 1, Content Security Policy 3, CSS Typed OM 1, CSSOM, File API, Image Resource, JSON-LD 1.1 Processing Algorithms and API, JSON-LD 1.1 Framing, Media Session, Payment Handler API, Presentation API, Push API, Secure Payment Confirmation, Service Workers, Trusted Types, UI Events, WebAssembly JavaScript Interface, Web Share API, Web Authentication, WebGPU, WebRTC 1.0, WebTransport, XMLHttpRequest; see also WebIDLPedia
UTC (algorithm) §: Defined in ECMAScript
utc (concept) §: Defined in Internationalization Glossary
Date.UTC(year, month, date, hours, minutes, seconds, ms) (WebIDL operation) §: Defined in ECMAScript
UTF-16BE (concept) §: Defined in Encoding; Referenced in HTML
UTF-16BE decoder (concept) §: Defined in Encoding
UTF-16BE/LE (concept) §: Defined in Encoding; Referenced in HTML
UTF-16LE (concept) §: Defined in Encoding; Referenced in HTML
UTF-16LE decoder (concept) §: Defined in Encoding
UTF-8 (concept) §: Defined in Encoding; Referenced in DOM, Fetch, HTML, URL, Web Share Target API, User Agent Interaction with Related Website Sets, Protected Audience, File API, Payment Method Manifest, Web Share API, XMLHttpRequest
UTF-8 decode (concept) §: Defined in Encoding; Referenced in Fetch, HTML, Infra, PNG, Web NFC API, WebDriver BiDi, Speculation Rules, Shared Storage API, Clipboard API and events, File API, Payment Method Manifest, Push API, Web Authentication, WebTransport, WebVTT: The Web Video Text Tracks Format
UTF-8 decode without BOM (concept) §: Defined in Encoding; Referenced in Fetch, HTML, URL, Web Bluetooth, WebSockets, Attribution Reporting, Cookie Store API, No-Vary-Search, URL Fragment Text Directives
UTF-8 decode without BOM or fail (concept) §: Defined in Encoding; Referenced in URL, WebDriver BiDi, WebAssembly JavaScript Interface: Content Security Policy, WebAssembly JavaScript Interface: Exception Handling, WebAssembly JavaScript Interface: Promise Integration, WebAssembly JavaScript Interface: Type Reflection, WebAssembly JavaScript Interface: Threading, Loading Signed Exchanges, WebAssembly JavaScript Interface
UTF-8 decoder (concept) §: Defined in Encoding
UTF-8 encode (concept) §: Defined in Encoding; Referenced in Federated Credential Management API, Fetch, File System, HTML, Infra, URL, PNG, Web NFC API, Web Share Target API, WebDriver BiDi, Web Bluetooth, WebSockets, Attribution Reporting, Cookie Store API, Scripting Policy, Shared Storage API, Clipboard API and events, Content Security Policy: Embedded Enforcement, Content Security Policy 3, File API, Push API, Web Authentication, Web Cryptography API, WebDriver, WebTransport, XMLHttpRequest
UTF-8 encoder (concept) §: Defined in Encoding
UTF-8 percent-encode (concept for string ) §: Defined in URL; Referenced in HTML, Protected Audience
SpeechSynthesisEvent.utterance (WebIDL attribute) §: Defined in Web Speech API
SpeechSynthesisEventInit.utterance (WebIDL dictionary member) §: Defined in Web Speech API
BluetoothRemoteGATTCharacteristic.uuid (WebIDL attribute) §: Defined in Web Bluetooth
BluetoothRemoteGATTDescriptor.uuid (WebIDL attribute) §: Defined in Web Bluetooth
BluetoothRemoteGATTService.uuid (WebIDL attribute) §: Defined in Web Bluetooth
UUID (WebIDL type alias) §: Defined in Web Bluetooth; Referenced in Web Bluetooth Scanning, Web Serial API; see also WebIDLPedia
BluetoothAdvertisingEvent.uuids (WebIDL attribute) §: Defined in Web Bluetooth
BluetoothAdvertisingEventInit.uuids (WebIDL dictionary member) §: Defined in Web Bluetooth
uvInitialized (algorithm for credential record ) §: Defined in Web Authentication
AuthenticationExtensionsClientInputs.uvm (WebIDL dictionary member) §: Defined in Web Authentication
AuthenticationExtensionsClientOutputs.uvm (WebIDL dictionary member) §: Defined in Web Authentication
UvmEntries (WebIDL type alias) §: Defined in Web Authentication; see also WebIDLPedia
UvmEntry (WebIDL type alias) §: Defined in Web Authentication; see also WebIDLPedia