The rel="alternate stylesheet" attribute for the <link> HTML element offers an alternative style option to users.

The AmbientLightSensor API returns the current light level in lux of the ambient light level around the device.

Anchor position container queries with the @container anchored(fallback: …) at-rule apply styles to an element based on the element's anchor position.

Anchor positioning places an element based on the position of another element. For example, you can place a tooltip next to the content it references.

The anchor() and anchor-size() CSS functions animate or transition on changes such as the anchor box moving or the anchor element changing.

Anchor positioned elements take CSS transforms on their anchor elements into account.

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 shortcuts web app manifest member registers common actions of an installed web app with the device. The device can present these actions to the user in contextually appropriate locations, such as jump lists on Windows or the app launcher on Android.

Asynchronous iteration of a stream allows you to use for await … of loops to iterate through a stream's incoming data.

The attribution reporting API measures when an ad click or view leads to a conversion, such as a purchase on an advertiser site.

The audioTracks and videoTracks APIs for media elements switch audio and video tracks during playback.

The navigator.audioSession API controls how audio playback interacts with other applications. For example, playing music can pause audio from other applications, while ambient audio can play at the same time.

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 setPosition() and setOrientation() methods of the AudioListener API set the virtual position and orientation of a person relative to sound sources, to spatialize audio in a Web Audio context.

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

The notRestoredReasons property of a PerformanceNavigationTiming object explains why the current document was blocked from using the back/forward cache (also known as the bfcache) on navigation.

Background fetch downloads data in the background even when the web page is closed.

The background synchronization API registers a service worker callback to run only when the device is no longer offline. You can use this to let users continue using your app while offline and synchronize with a server after reconnecting.

The navigator.setAppBadge() method allows installed web applications to display an application badge, typically a dot or number shown alongside the application's icon on the device's home screen or application dock.

The BarcodeDetector API recognizes various barcode formats in images.

The navigator.getBattery() API obtains information about the device's battery, including charge level and status. Also known as the Battery API.

COEP violation reporting sends a report to a URL nominated by the Reporting-Endpoints header or the ReportingObserver API when a page violates its Cross-Origin-Embedder-Policy policy.

COLRv1 is a font format that supports multi-color glyphs. COLRv1 extends COLRv0 to support gradients, transforms, and blending modes.

The PressureObserver API monitors CPU load, allowing you to adjust workloads in response to available computing resources. Also known as the Compute Pressure API.

Module import … with { type: "css" } statements load CSS modules as constructable stylesheets. Also known as CSS module scripts.

The DOM level 2 style specification defined interfaces to access and modify CSS styles, such as CSSValue and CSSPrimitiveValue, that were later excluded from the CSS object model.

The CSSStyleValue and its subclasses represent CSS values as distinct types instead of only strings. Also known as typed OM.

The capture handle API allows you to share a custom handle (a string) from a web application being captured by getDisplayMedia() to the capturing web application.

The s identifier in a CSS attribute selector matches attribute values case-sensitively in document languages like HTML where attribute values are case-insensitive.

The Clear-Site-Data header deletes browsing data (such as cookies, storage, or cache) associated with the requesting website.