WebPlatformFeatures Class

Gets or sets whether the CSS Animation Worklet API is exposed (https://drafts.css-houdini.org/css-animation-worklet-1/): CSS.animationWorklet (and the Worklet interface) and the WorkletAnimation interface. The animation worklets also need a script engine that supports the module scripts. The default is true.

Gets or sets whether the asynchronous clipboard API is exposed (https://w3c.github.io/clipboard-apis/#async-clipboard-api): navigator.clipboard and the Clipboard, ClipboardItem and ClipboardChangeEvent interfaces. The copy, cut and paste actions are not affected (see BrowsingContextOptions.ClipboardPermission). The default is true.

Gets or sets whether the Badging API is exposed (https://w3c.github.io/badging/): navigator.setAppBadge() and navigator.clearAppBadge(), in the windows and the workers (see BrowsingContextOptions.Badging). The default is true.

Gets or sets whether the Battery Status API is exposed (https://w3c.github.io/battery/): navigator.getBattery() and the BatteryManager interface (see BrowsingContextOptions.BatteryStatus). The default is true.

Gets or sets whether navigator.sendBeacon() is exposed (https://w3c.github.io/beacon/). The default is true.

Gets or sets whether the BroadcastChannel interface is exposed (https://html.spec.whatwg.org/multipage/web-messaging.html#broadcasting-to-other-browsing-contexts). The default is true.

Gets or sets whether the Cache API is exposed (https://w3c.github.io/ServiceWorker/#cache-objects): caches, Cache and CacheStorage, in the secure contexts, when WebPlatformFeatures.FetchEnabled is true. The default is true.

Gets or sets whether the 2D contexts of the canvases are exposed (https://html.spec.whatwg.org/multipage/canvas.html#2dcontext): the CanvasRenderingContext2D, CanvasGradient, CanvasPattern, TextMetrics, Path2D, OffscreenCanvas and OffscreenCanvasRenderingContext2D interfaces; when disabled, getContext("2d") returns null. The 2D contexts also need a rendering backend (BrowsingContextOptions.RenderingBackend). The default is true.

Gets or sets whether the client hints are enabled (https://wicg.github.io/client-hints-infrastructure/, https://wicg.github.io/ua-client-hints/): navigator.userAgentData and the NavigatorUAData interface. When disabled, no client hint is sent with the requests either (the Sec-CH-* headers), and the Accept-CH and Critical-CH headers and the <meta http-equiv="delegate-ch"> elements are ignored. The default is true.

Gets or sets whether the CloseWatcher interface is exposed (https://html.spec.whatwg.org/multipage/interaction.html#the-closewatcher-interface). The close requests of the user still close the dialogs and the popovers. The default is true.

Gets or sets whether the CompressionStream and DecompressionStream interfaces are exposed (https://compression.spec.whatwg.org/). The default is true.

Gets or sets whether the Compute Pressure API is exposed (https://w3c.github.io/compute-pressure/): the PressureObserver and PressureRecord interfaces, in the windows and the workers (see BrowsingContextOptions.ComputePressure). The default is true.

Gets or sets whether the Container Timing API is exposed (https://w3c.github.io/container-timing/): the PerformanceContainerTiming interface, the container entry type and HTMLElement.containerTiming and containerTimingIgnore. The paints of a document are computed once one of its elements has a containertiming attribute. The default is true.

Gets or sets whether the Cookie Store API is exposed (https://cookiestore.spec.whatwg.org/): cookieStore, CookieStore and CookieChangeEvent. document.cookie is not affected. The default is true.

Gets or sets whether the CSS Parser API is exposed (https://wicg.github.io/css-parser-api/, a draft that no browser implements): CSS.parseStylesheet(), CSS.parseRuleList(), CSS.parseRule(), CSS.parseDeclarationList(), CSS.parseDeclaration(), CSS.parseValue(), CSS.parseValueList(), CSS.parseCommaValueList() and the CSSParserRule, CSSParserAtRule, CSSParserQualifiedRule, CSSParserDeclaration, CSSParserValue, CSSParserBlock and CSSParserFunction interfaces. The default is true.

Gets or sets whether the tentative extensions of the template elements that patch content are supported (the declarative partial updates, https://github.com/WICG/declarative-partial-updates/blob/main/fragment-include-explainer.md): the buffer, sanitize and src attributes, and HTMLTemplateElement.buffer. The patching of the targeted markers (https://html.spec.whatwg.org/multipage/scripting.html#prepare-content-patching) is supported either way. The default is true.

Gets or sets whether the Worker interface is exposed: the dedicated workers (https://html.spec.whatwg.org/multipage/workers.html#dedicated-workers-and-the-worker-interface). The default is true.

Gets the default features: all the features are enabled.

Gets or sets whether the Device Memory API is exposed (https://www.w3.org/TR/device-memory/): navigator.deviceMemory, in the secure windows and workers (see ClientHintsOptions.DeviceMemory). The default is true.

Gets or sets whether the device orientation and motion events are exposed (https://w3c.github.io/deviceorientation/): DeviceOrientationEvent, DeviceMotionEvent, DeviceMotionEventAcceleration, DeviceMotionEventRotationRate and the ondeviceorientation, ondeviceorientationabsolute and ondevicemotion event handlers of the window (see BrowsingContextOptions.Sensors). The default is true.

Gets or sets whether the Device Posture API is exposed (https://w3c.github.io/device-posture/): navigator.devicePosture and the DevicePosture interface (see BrowsingContextOptions.DevicePosture). The device-posture media feature is evaluated whatever the value. The default is true.

Gets or sets whether Document Policy is supported (https://wicg.github.io/document-policy/): the Document-Policy, Document-Policy-Report-Only and Require-Document-Policy headers, the Sec-Required-Document-Policy request header and the policy attribute of the iframe elements. When it is false, the headers are ignored and HTMLIFrameElement.policy is hidden. The default is true.

Gets or sets whether the Element Timing API is exposed (https://w3c.github.io/element-timing/): the PerformanceElementTiming interface, the element entry type and Element.elementTiming. The default is true.

Gets or sets whether the EventSource interface is exposed: the server-sent events (https://html.spec.whatwg.org/multipage/server-sent-events.html). The default is true.

Gets or sets whether the Event Timing API is exposed (https://w3c.github.io/event-timing/): the PerformanceEventTiming and EventCounts interfaces, performance.eventCounts, performance.interactionCount and the event and first-input entry types. When it is disabled, the trusted events of the user input are not timed (and they schedule no rendering update of the event loop). The default is true.

Gets or sets whether fetch() and the Request, Response and Headers interfaces are exposed (https://fetch.spec.whatwg.org/#fetch-api). The default is true.

Gets or sets whether the deferred fetching is exposed (https://fetch.spec.whatwg.org/#deferred-fetch): fetchLater() and FetchLaterResult, in the windows. They are also hidden when WebPlatformFeatures.FetchEnabled is false. The default is true.

Gets or sets whether the origin private file system is exposed (https://fs.spec.whatwg.org/): navigator.storage.getDirectory(), FileSystemHandle, FileSystemFileHandle, FileSystemDirectoryHandle, FileSystemWritableFileStream and FileSystemSyncAccessHandle. The default is true.

Gets or sets whether the Fullscreen API is exposed (https://fullscreen.spec.whatwg.org/): Element.requestFullscreen(), document.exitFullscreen(), fullscreenElement, fullscreenEnabled, fullscreen, and the onfullscreenchange and onfullscreenerror event handlers. The default is true.

Gets or sets whether the Geolocation API is exposed (https://w3c.github.io/geolocation/): navigator.geolocation and the Geolocation, GeolocationPosition, GeolocationCoordinates and GeolocationPositionError interfaces (see BrowsingContextOptions.Geolocation). The default is true.

Gets or sets whether Global Privacy Control is exposed (https://w3c.github.io/gpc/): navigator.globalPrivacyControl, in the windows and the workers (see BrowsingContextOptions.GlobalPrivacyControl, which also sends the Sec-GPC header). The default is true.

Gets or sets whether the Idle Detection API is exposed (https://wicg.github.io/idle-detection/): the IdleDetector interface, in the windows and the dedicated workers (see BrowsingContextOptions.IdleDetection). The default is true.

Gets or sets whether IndexedDB is exposed (https://w3c.github.io/IndexedDB/): indexedDB and the IDB* interfaces. The default is true.

Gets or sets whether navigator.scheduling.isInputPending() is exposed (https://wicg.github.io/is-input-pending/): the Scheduling interface and navigator.scheduling (see BrowsingContextOptions.PendingInput). The default is true.

Gets or sets whether the IntersectionObserver and IntersectionObserverEntry interfaces are exposed (https://w3c.github.io/IntersectionObserver/), and whether the loading="lazy" images and iframes are loaded lazily (https://html.spec.whatwg.org/multipage/urls-and-fetching.html#lazy-loading-attributes): when disabled, they are loaded at once as with loading="eager", so a document whose scripts never read the geometry is never laid out. The default is true.

Gets or sets whether the Keyboard Lock API is exposed (https://wicg.github.io/keyboard-lock/): navigator.keyboard and the Keyboard interface (see BrowsingContextOptions.KeyboardLock). The default is true.

Gets or sets whether the Keyboard Map API is exposed (https://wicg.github.io/keyboard-map/): navigator.keyboard.getLayoutMap(), navigator.keyboard.onlayoutchange and the KeyboardLayoutMap interface (see BrowsingContextOptions.KeyboardMap). navigator.keyboard is hidden when both this API and the Keyboard Lock API (WebPlatformFeatures.KeyboardLockEnabled) are disabled. The default is true.

Gets or sets whether the Largest Contentful Paint API is exposed (https://w3c.github.io/largest-contentful-paint/): the LargestContentfulPaint interface and the largest-contentful-paint entry type. The default is true.

Gets or sets whether the Layout Instability API is exposed (https://wicg.github.io/layout-instability/): the LayoutShift and LayoutShiftAttribution interfaces and the layout-shift entry type of the performance observers. The layout shifts of a document are only computed once a performance observer of its window observes them, so a document whose scripts never read the geometry is never laid out. The default is true.

Gets or sets whether the CSS Layout API is enabled (https://drafts.css-houdini.org/css-layout-api-1/): CSS.layoutWorklet (and the Worklet interface), and the layout of the display: layout() boxes by the registered layout classes; when disabled, these boxes are flow-root block containers. The layout worklets also need a script engine that supports the module scripts. The default is true.

Gets or sets whether the Long Tasks API is exposed (https://w3c.github.io/longtasks/): the PerformanceLongTaskTiming and TaskAttributionTiming interfaces and the longtask entry type. The tasks of the event loop that run scripts for 50 milliseconds or more are reported to the windows of their pages. The default is true.

Gets or sets whether HTMLVideoElement.getVideoPlaybackQuality() and the VideoPlaybackQuality interface are exposed (https://w3c.github.io/media-playback-quality/). The default is true.

Gets or sets whether the Media Session API is exposed (https://w3c.github.io/mediasession/): navigator.mediaSession and the MediaSession, MediaMetadata and ChapterInformation interfaces (see BrowsingContextOptions.MediaSession). The default is true.

Gets or sets whether the Media Source Extensions are exposed (https://w3c.github.io/media-source/): the MediaSource, MediaSourceHandle, SourceBuffer, SourceBufferList, ManagedMediaSource, ManagedSourceBuffer and BufferedChangeEvent interfaces and the sourceBuffer attribute of the audio, video and text tracks. They need a media backend that parses the byte streams (MediaBackend.CreateSegmentParser): without one, no type is supported. The default is true.

Gets or sets whether the navigation API is exposed (https://html.spec.whatwg.org/multipage/nav-history-apis.html#navigation-api): navigation and the Navigation* interfaces. The default is true.

Gets or sets whether the Navigation Timing API is exposed (https://w3c.github.io/navigation-timing/): the PerformanceNavigationTiming, PerformanceTiming and PerformanceNavigation interfaces, performance.timing and performance.navigation, and the navigation entry type. The default is true.

Gets or sets whether the Network Information API is exposed (https://wicg.github.io/netinfo/): navigator.connection and the NetworkInformation interface, in the windows and the workers (see BrowsingContextOptions.NetworkInformation). The default is true.

Gets or sets whether the Notifications API is exposed (https://notifications.spec.whatwg.org/): the Notification interface (see BrowsingContextOptions.ShowNotification). The default is true.

Gets or sets whether the Observable API is exposed (https://wicg.github.io/observable/): the Observable and Subscriber interfaces and EventTarget.prototype.when(). The default is true.

Gets or sets whether the Page Lifecycle API is exposed (https://wicg.github.io/page-lifecycle/): the onfreeze, onresume and wasDiscarded members of Document. The documents are frozen and resumed whatever its value (see BrowsingContext.IsFrozen). The default is true.

Gets or sets whether the Paint Timing API is exposed (https://w3c.github.io/paint-timing/): the PerformancePaintTiming interface and the paint entry type (the first paint and the first contentful paint). The paints of a document are only computed once a script of its window observes or reads the paint timing entries, so a document whose scripts never do it is never laid out nor painted for them. The default is true.

Gets or sets whether the CSS Painting API is enabled (https://drafts.css-houdini.org/css-paint-api-1/): CSS.paintWorklet (and the Worklet interface), and the paint() images, which are invalid images when disabled. The paint worklets also need a script engine that supports the module scripts and a rendering backend (BrowsingContextOptions.RenderingBackend). The default is true.

Gets or sets whether the PermissionsPolicy interface, document.permissionsPolicy and iframe.permissionsPolicy are exposed (https://w3c.github.io/webappsec-permissions-policy/#introspection). The permissions policies of the documents are enforced either way. The default is true.

Gets or sets whether the Pointer Lock API is exposed (https://w3c.github.io/pointerlock/): Element.requestPointerLock(), document.exitPointerLock(), pointerLockElement, and the onpointerlockchange and onpointerlockerror event handlers. The default is true.

Gets or sets whether Prioritized Task Scheduling is exposed (https://wicg.github.io/scheduling-apis/): scheduler (postTask(), yield()), Scheduler, TaskController, TaskSignal and TaskPriorityChangeEvent. The default is true.

Gets or sets whether the ReportingObserver interface is exposed (https://w3c.github.io/reporting/#reportingobserver). The reports are still generated and delivered to the endpoints of the Reporting-Endpoints header. The default is true.

Gets or sets whether the ResizeObserver, ResizeObserverEntry and ResizeObserverSize interfaces are exposed (https://drafts.csswg.org/resize-observer-1/). Without resize observers, a document whose scripts never read the geometry is never laid out. The default is true.

Gets or sets whether the Screen Orientation API is exposed (https://w3c.github.io/screen-orientation/): screen.orientation and the ScreenOrientation interface (see BrowsingContextOptions.ScreenOrientation). The default is true.

Gets or sets whether the scroll-driven animations are enabled (https://drafts.csswg.org/scroll-animations-1/): the ScrollTimeline and ViewTimeline interfaces and the rangeStart and rangeEnd members of Animation. When disabled, the scroll progress and view progress timelines of the styles (animation-timeline: scroll(), view() and the named timelines) are inactive, so a document is never laid out for them. The default is true.

Gets or sets whether the sensor APIs are exposed (https://w3c.github.io/sensors/): Sensor, SensorErrorEvent, Accelerometer, LinearAccelerationSensor, GravitySensor, Gyroscope, Magnetometer, UncalibratedMagnetometer, AmbientLightSensor, ProximitySensor, OrientationSensor, AbsoluteOrientationSensor and RelativeOrientationSensor (see BrowsingContextOptions.Sensors). The default is true.

Gets or sets whether the service workers are exposed (https://w3c.github.io/ServiceWorker/): navigator.serviceWorker and the interfaces of the service workers, in the secure contexts. When it is false, no service worker is registered or run, and the requests are not intercepted. The default is true.

Gets or sets whether the SharedWorker interface is exposed: the shared workers (https://html.spec.whatwg.org/multipage/workers.html#shared-workers-and-the-sharedworker-interface). The default is true.

Gets or sets whether the soft navigations are detected (https://wicg.github.io/soft-navigations/): the PerformanceSoftNavigation and InteractionContentfulPaint interfaces and the soft-navigation and interaction-contentful-paint entry types. The interactions of the user are the ones of the Event Timing API: the soft navigations are only detected when WebPlatformFeatures.EventTimingEnabled is true. The default is true.

Gets or sets whether the speculation rules are supported (https://html.spec.whatwg.org/multipage/speculative-loading.html): the speculationrules script type (HTMLScriptElement.supports("speculationrules")), the Speculation-Rules header, and the prerendering API (document.prerendering, the prerenderingchange event and PerformanceNavigationTiming.activationStart). When it is false, nothing is prefetched nor prerendered. The default is true.

Gets or sets whether the storage manager of the Storage Standard is exposed (https://storage.spec.whatwg.org/): navigator.storage and StorageManager. When it is false, the origin private file system is not exposed either (see WebPlatformFeatures.FileSystemEnabled). The default is true.

Gets or sets whether the SVG animations run (SMIL, https://svgwg.org/specs/animations/): the animate, set, animateMotion and animateTransform elements, and the TimeEvent interface. When disabled, the animation elements have no effect and fire no event. The default is true.

Gets or sets whether the URL text directives are enabled (https://wicg.github.io/scroll-to-text-fragment/): the FragmentDirective interface and document.fragmentDirective. When disabled, the fragment directive (#:~:text=...) is a part of the fragment of the URL as any other text: it is neither removed nor searched. The default is true.

Gets or sets whether the text tracks of the media elements are enabled (https://html.spec.whatwg.org/multipage/media.html#timed-text-tracks, https://w3c.github.io/webvtt/): the TextTrack, TextTrackList, TextTrackCue, TextTrackCueList, VTTCue and VTTRegion interfaces, HTMLMediaElement.textTracks, HTMLMediaElement.addTextTrack() and HTMLTrackElement.track. When disabled, the resources of the track elements are not fetched and no track is enabled automatically, so no cue is rendered. The default is true.

Gets or sets whether the Touch Events are enabled (https://w3c.github.io/touch-events/): the Touch, TouchList and TouchEvent interfaces, and the touchstart, touchmove, touchend and touchcancel events of the touch pointers of the user (see UserInput). The default is true.

Gets or sets whether the URLPattern interface is exposed (https://urlpattern.spec.whatwg.org/). The default is true.

Gets or sets whether the User Timing API is exposed (https://w3c.github.io/user-timing/): the PerformanceMark and PerformanceMeasure interfaces, performance.mark(), measure(), clearMarks() and clearMeasures(), and the mark and measure entry types. The default is true.

Gets or sets whether the Vibration API is exposed (https://w3c.github.io/vibration/): navigator.vibrate() (see BrowsingContextOptions.Vibrate). The default is true.

Gets or sets whether the view transitions are enabled (https://drafts.csswg.org/css-view-transitions-1/): document.startViewTransition(), document.activeViewTransition, element.startViewTransition(), element.activeViewTransition and the ViewTransition and ViewTransitionTypeSet interfaces. When disabled, the members and the interfaces are not exposed to the scripts (the view-transition-* properties and the pseudo-elements are still parsed). The default is true.

Gets or sets whether the VirtualKeyboard API is exposed (https://w3c.github.io/virtual-keyboard/): navigator.virtualKeyboard, the VirtualKeyboard interface and the virtualKeyboardPolicy attribute (see BrowsingContextOptions.VirtualKeyboard). The default is true.

Gets or sets whether the visibility state entries are exposed (https://html.spec.whatwg.org/multipage/interaction.html#the-visibilitystateentry-interface): the VisibilityStateEntry interface and the visibility-state entry type. document.visibilityState and the visibilitychange event are not affected. The default is true.

Gets or sets whether the Screen Wake Lock API is exposed (https://w3c.github.io/screen-wake-lock/): navigator.wakeLock and the WakeLock and WakeLockSentinel interfaces (see BrowsingContextOptions.WakeLock). The default is true.

Gets or sets whether the WebAssembly namespace is exposed (https://webassembly.github.io/spec/js-api/), when BrowsingContextOptions.WebAssemblyRuntime is set. The default is true.

Gets or sets whether the Web Cryptography API is exposed (https://w3c.github.io/webcrypto/): crypto, Crypto, SubtleCrypto and CryptoKey. The default is true.

Gets or sets whether the Web Locks API is exposed (https://w3c.github.io/web-locks/): navigator.locks, LockManager and Lock. The default is true.

Gets or sets whether the Web Share API is exposed (https://w3c.github.io/web-share/): navigator.share() and navigator.canShare() (see BrowsingContextOptions.Share). The default is true.

Gets or sets whether the WebSocket interface is exposed (https://websockets.spec.whatwg.org/). The default is true.

Gets or sets whether the Web Storage API is exposed (https://html.spec.whatwg.org/multipage/webstorage.html): localStorage, sessionStorage, Storage and StorageEvent. The default is true.

Gets or sets whether the XMLHttpRequest interface is exposed (https://xhr.spec.whatwg.org/). The default is true.