An AudioListener object represents the virtual position and orientation of a person relative to sound sources, to spatialize audio in a Web Audio context.

The EXT_float_blend extension for WebGL 1.0 and 2.0 contexts adds 32-bit floating-point components to blending and draw buffers.

The Request.formData() and Response.formData() methods read a request or response body and return a FormData promise. You can use it to access the fields of a form submission.

The KHR_parallel_shader_compile extension for WebGL 1.0 and 2.0 contexts checks the status of shader compilation without blocking the runtime.

The window.performance.timing and window.performance.navigation APIs report performance timing information for events that occur during the loading and use of the current page.

The WEBGL_compressed_texture_s3tc_srgb extension for WebGL 1.0 and 2.0 contexts adds S3TC compressed texture formats for the sRGB colorspace to compressedTexImage2D() and compressedTexSubImage2D().

The WebVTT cue alignment settings control which part of the cue is aligned with the given line and position. Cue alignment is set using line and position settings in WebVTT files or the lineAlign and positionAlign properties of VTTCue using JavaScript.

WebVTT regions set the areas of the video where captions or subtitles should be rendered, such as placing roll-up captions used for live captions.

The display: ruby CSS declaration renders an element with the box layout of a <ruby> HTML element. Child elements may use equivalents to <ruby> internal elements such as display: ruby-base for <rb>.

An XRDepthInformation object represents a measurement of the distance from the user's device to the real-world geometry in the user's environment.

The XRLightProbe and XRLightEstimate objects represent real-world environmental lighting conditions during a WebXR session.

The Sec-CH-UA HTTP request header and the navigator.userAgentData API expose browser and platform information used to vary responses and application logic. User agent client hints are similar to user agent strings but more privacy-preserving and safer to parse.

The measureUserAgentSpecificMemory() method estimates the memory usage of a web application including all its iframes and workers.

The share_target web app manifest member registers an installed web app as a handler for shared content. When a user shares content by using the device share dialog, the installed app can be listed as an option for handling the shared content.

The WebHID API provides access to Human Interface Devices (HID) that are connected to the user's device.

The cookieStore.get() method returns cookie metadata, such as the domain, expires, path, sameSite and secure properties.

The navigator.scheduling.isInputPending() method checks if there are pending input events, such as touch or mouse events. This allows you to yield from long-running scripts that might be blocking user interaction.

The ::marker CSS pseudo-element selects list item markers for styling numbers or bullets.

The "immersive-ar" value for navigator.xr.requestSession() starts an augmented reality WebXR session that renders content aligned with the visible environment.

An XRAnchor object keeps track of a pose that is fixed relative to the real world. Anchors build an illusion that the placed objects are really present in the user's environment.

The related_applications web app manifest member lists operating system-specific applications that are related to the current web app, such as an Android app that provides similar functionality. The getInstalledRelatedApps() method lists which of those are installed on the current device.

A document's bgColor, fgColor, alinkColor, linkColor, and vlinkColor properties get and set the background, foreground, active link, link, and visited link colors of that document.

The capture HTML attribute for <input type="file"> elements allows the user to capture media using the device's camera or microphone.

SharedArrayBuffer objects can be used in WebGL APIs that previously only worked with ArrayBuffer objects.

The document.open(), document.write(), document.writeln(), and document.close() methods write content to a document, possibly while that document is still loading.

The document.execCommand() method reads and writes from the clipboard and performs editing commands on editable text, such as changing the font name or style. Related methods check whether commands are supported, enabled, or applied.

The user-select CSS property controls which elements can be selected by the user.

The Content Index API allows developers to register their offline enabled content with the browser.

A layout-shift performance entry measures the layout stability of web pages based on movements of the elements on the page. They're used to calculate cumulative layout shift (CLS), a common metric for perceived stability.

A DOM overlay shows 2D DOM content as an interactive, transparent layer on top of a WebXR application's WebGL content and camera image.