The SpeechRecognition.grammars property of the Web Speech API represents a set of words or patterns of words that the recognition service should recognize, used for when the recognition service's accuracy is low.

The cancel() method of a TransformStream transformer cleans up resources when the readable side cancels or the writable side aborts.

The getBoxQuads() method, when called on a document, element, pseudo-element, or text node, returns the list of DOMQuad objects that represent the CSS boxes used to render the node.

The color-contrast() CSS function picks a color from a list that has the most contrast with another color.

The <portal> HTML element embeds another page into the current page as a non-interactive preview.

Module import … assert { type: "json" } and import … assert { type: "css" } JavaScript statements load JSON and CSS data.

The navigator.getVRDisplays() API represents virtual reality (VR) devices, including sensors and head-mounted displays.

Mutation events like DOMSubtreeModified, DOMNodeInserted, or DOMNodeRemoved fire when DOM changes occur.

The Access-Control-Request-Private-Network: true and Access-Control-Allow-Private-Network: true HTTP request and response headers establish permission for websites to make requests to internal networks, such as to routers.

The Magnetometer API reads magnetic field sensor data from the device's magnetometer.

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

The :target-within CSS pseudo-class matches the element with an ID matching the URL fragment and its ancestors.

The line-height-step CSS property creates consistent vertical rhythm by setting the spacing between body text baselines. It rounds taller lines like headings up to the next multiple of the body text spacing.

The display: contents CSS declaration sets an element to display only its contents, not itself.

The image() CSS function creates an image similar to url() but with additional functionality. It can create a solid color as an image, provide a fallback from an image URL to a solid color, or clip a sprite image using media fragments. Not to be confused with the Image() constructor.

The speak CSS property sets whether or not text should be spoken.

The fit-content() CSS function, used outside of a grid layout property, clamps a length between min-content and max-content.

The element() CSS function creates a live-updating image from an HTML element that can be used as an image or background image.

The prefers-reduced-data CSS media query detects whether the user has a preference for using less network traffic. For example, you can use this media query to avoid loading large font files and use a system font instead.

The WebNN API constructs and executes computational graphs of neural networks by making use of the various machine learning capabilities and hardware accelerators available on the device. Also known as Web Neural Network API.

The line-clamp CSS property limits the text in a block container to a certain number of lines. The prefixed -webkit-line-clamp is widely supported but only works with -webkit-box-orient: vertical in combination with display: -webkit-box or display: -webkit-inline-box.

The <fencedframe> element embeds another HTML page into the current page in a more secure and privacy-preserving way than <iframe> elements.

The @mixin and @apply CSS at-rules define reusable style declaration fragments and apply them inside rules, optionally passing arguments.

A container performance entry measures time to render child elements, for container elements that have the containertiming attribute.

The EXT_disjoint_timer_query extension for WebGL 1.0 contexts measures the duration of a set of GL commands, without stalling the rendering pipeline.

The sharedStorage API stores data to a shared space where the data can then be processed without the ability to track users across the different sites they visit. A common use case is measuring the reach of third-party ads without using user-tracking cookies.