The document picture-in-picture API creates an always-on-top window from arbitrary HTML content.

The navigator.serial API communicates with devices over serial ports, such as microcontrollers.

The hanging-punctuation CSS property puts punctuation characters outside of the box to align the text with the rest of the document.

An Origin object represents an origin, as in a scheme, hostname, and port. You can use it to make same-site and same-origin comparisons.

The LanguageDetector API identifies the likely natural language that some text is written in. You can use this API to supplement machine translation when the source source language is not known.

The extendedLifetime option of the SharedWorker() constructor gives shared workers extra time to perform operations after all pages using it have been navigated away from or closed.

The Translator API translates some text from one natural language to another, using machine translation.

The at-rule() function, when used with @supports, checks if a CSS at-rule is supported. For example @supports at-rule(@starting-style) checks if the @starting-style at-rule is supported.

The LanguageModel API prompts an on-device language model. Also known as the Prompt API.

The sizes="auto" attribute for the <img> HTML element sets the layout size for the image based on the computed layout size when choosing a source from the srcset. This attribute only applies to images with the loading="lazy" attribute.

The CSS.highlights.highlightsFromPoint() method returns an array of Highlight objects at a specified point.

The :playing, :paused, :seeking, :buffering, :stalled, :muted, and :volume-locked CSS pseudo-classes match <audio> and <video> elements based on their state.

The color-mix() CSS function accepts three or more colors.

The overscroll-behavior CSS property disables default scrolling behaviors when the edges of a scrolling area are reached.

The startViewTransition() method of an Element object starts a view transition that affects only that element's DOM tree. You can use this to run separate elements' transitions concurrently.

WebXR layer types, such as XRCylinderLayer, XRCylinderLayer, XREquirectLayer, XRProjectionLayer or XRQuadLayer, are managed by the system compositor, to reduce latency or resampling.

The border-shape CSS property sets the geometry of the border box, changing the shape of any applicable border, border image, focus outline, or shadow.

The CloseWatcher API listens and responds to close requests on in-page components, such as modals, popovers, and sidebars.

Crash reporting sends a report to a URL nominated by the Reporting-Endpoints header when a user is unable to continue using the page because the browser or tab crashed.

The display: grid-lanes and display: inline-grid-lanes CSS declarations create a layout where items are tightly packed in parallel lanes. Items are placed one by one in the lane that has the most available space. Also known as masonry.

The captureStream() method for <audio> and <video> elements returns a MediaStream for the media element's content. You can use this to record media or send it elsewhere, such as a canvas or WebRTC connection.

The <meta name="text-scale" content="scale" /> HTML element allows the browser's initial font size to be affected by the operating system text scale settings. The <meta name="text-scale" content="legacy" /> element is the default behavior that respects only browser font-size settings.

The precommitHandler callback option to NavigateEvent's intercept() method returns a promise that defers navigation until the promise resolves. You can use this to change the navigation's URL, state, and history before navigation occurs.

The Sanitizer API customizes the sanitization of HTML parsed and inserted into the DOM in a way that can prevent cross-site scripting attacks. You can use it with DOM APIs that accept a sanitizer option, such as parseHTML() or setHTML().

The CustomElementRegistry() constructor creates a new custom element registry that's separate from the global window.customElements registry. Creating more than one registry is useful for multiple custom elements that have the same tag name to coexist.

The hidden="until-found" attribute hides an element until it is found using the browser's find-in-page search or it is directly navigated to by following a URL fragment.

The overflow-clip-margin CSS property sets how far overflow content may appear outside the bounds of an element before it's clipped by effects such as overflow: clip.

The window.crashReport object is a key-value store to record information about your application's state. If there's a crash, then the data in the key-value store is sent to your crash reporting endpoint, to help you pinpoint the cause of the crash.

The confidence property of a navigation performance entry describes whether the navigation metric is likely to be representative the page's performance (high confidence) or affected by transient conditions, such as browser startup (low confidence).

The text-justify CSS property sets the justification method of text when text-align: justify is set.