View transitions: Inherit more animation properties

Chrome 140
Stable release date: September 2nd, 2025

CSS
CSS typed arithmetic
Typed arithmetic lets you write expressions in CSS such as calc(10em / 1px) or calc(20% / 0.5em * 1px). This is useful in, for example, typography, as it lets you convert a typed value into an untyped one and reuse it for number accepting properties. Another use case is to multiply the unitless value by another type. For example, you can now cast from pixels to degrees.

CSS caret-animation property
Chromium supports animation of the caret-color property. However, when animated, the caret's default blinking behavior interferes with the animation.

The CSS caret-animation property has two possible values: auto and manual. auto means browser default (blinking), and manual means the developer controls the caret animation. Additionally, users who are disturbed by or have adverse reactions to blinking or flashing visuals can disable the blinking with a user stylesheet.

highlightsFromPoint API
The highlightsFromPoint API lets developers interact with custom highlights. It detects which highlights exist at a specific point within a document. This interactivity is valuable for complex web features where multiple highlights may overlap or exist within shadow DOM. By providing precise point-based highlight detection, the API empowers developers to manage dynamic interactions with custom highlights more effectively. For example, developers can respond to user clicks or hover events on highlighted regions to trigger custom tooltips, context menus, or other interactive features.

ScrollIntoView container option
The ScrollIntoViewOptions container option allows developers to perform a scrollIntoView operation that only scrolls the nearest ancestor scroll container. For example, the following snippet only scrolls the scroll container of target to bring target into view, but won't scroll all of the scroll containers to the viewport:

View transitions: Inherit more animation properties
Adds more animation properties to inherit through the view transition pseudo tree:

• animation-timing-function
• animation-iteration-count
• animation-direction
• animation-play-state

View transition pseudos inherit animation-delay.
In addition to the previous update, the animation-delay property is now inherited through the view transition pseudo tree.

Nested view transitions groups
This feature allows view transitions to generate a nested pseudo-element tree rather than a flat one. This allows the view transition to appear more in line with its original elements and visual intent. It enables clipping, nested 3D transforms, and proper application of effects like opacity, masking, and filters.

Propagate viewport overscroll-behavior from root
This change propagates overscroll-behavior from the root instead of the body.

The CSS working group resolved not to propagate properties from the

to the viewport. Instead, properties of the viewport propagate from the root () element. As such, overscroll-behavior should propagate from the root element. However, Chrome has had a longstanding issue: it propagates overscroll-behavior from the rather than the root. This behavior is not interoperable with other browsers. This change makes Chrome comply with the specification and become interoperable with other implementations.

CSS counter() and counters() in alt text of content property
This feature adds the ability to use counter() and counters() in the alt text of the content property. This provides more meaningful information to improve accessibility.

CSS scroll-target-group property
The scroll-target-group property specifies whether the element is a scroll marker group container. It accepts one of the following values:

'none': The element does not establish a scroll marker group container.
'auto': The element establishes a scroll marker group container forming a scroll marker group containing all of the scroll marker elements for which this is the nearest ancestor scroll marker group container.
Establishing a scroll marker group container lets any anchor HTML elements with a fragment identifier that are inside such a container to be the HTML equivalent of ::scroll-marker pseudo-elements. The anchor element whose scroll target is currently in view can be styled using the :target-current pseudo-class.

Support font-variation-settings descriptor in @font-face rule
CSS allows developers to adjust a font's weight, width, slant, and other axes using the font-variation-settings property on individual elements. However, Chromium-based browsers lack support for this property within @font-face declarations. This feature supports the string-based syntax for font-variation-settings as defined in CSS Fonts Level 4. Invalid or unrecognized feature tags are ignored per specification. No binary or non-standard forms are supported. Variable fonts are becoming more widely adopted for both performance and typographic flexibility. Adding support for this descriptor in Chromium enhances control, reduces repetition, and supports a more scalable, modern approach to web typography.

DOM
ToggleEvent source attribute
The source attribute of a ToggleEvent contains the element that triggered the ToggleEvent to be fired, if applicable. For example, if a user clicks a <button> element with the popovertarget or commandfor attribute set to open a popover, the ToggleEvent fired on the popover will have its source attribute set to the invoking

Isolated Web Apps (IWAs)
Controlled Frame API (available only to IWAs)
This feature adds a Controlled Frame API available only to Isolated Web Apps (IWAs). Like similarly-named APIs on other platforms, Controlled Frame allows embedding all content, even third-party content that cannot be embedded in <iframe>. Controlled Frame also allows controlling embedded content with a collection of API methods and events. For more information about Isolated Web Apps

JavaScript
Uint8Array to and from base64 and hex
Base64 is a common way to represent arbitrary binary data as ASCII. JavaScript has Uint8Arrays for binary data. However, it lacks a built-in mechanism to encode that data as base64, or to take base64 data and produce a corresponding Uint8Array. This feature adds the ability and methods for converting between hex strings and Uint8Arrays

View transition finished promise timing change
The current finished promise timing happens within the rendering lifecycle steps. This means that code that runs as a result of promise resolution happens after the visual frame that removes the view transition has been produced. This can cause a flicker at the end of the animation if the script moves styles to preserve a visually similar state. This change resolves the issue by moving the view transition cleanup steps to run asynchronously after the lifecycle is completed.

Web APIs
ReadableStreamBYOBReader min option
This feature introduces a min option to the existing ReadableStreamBYOBReader.read(view) method. The method already accepts an ArrayBufferView into which it reads data, but currently does not guarantee how many elements are written before the read resolves. By specifying a min value, you can require that the stream wait until at least that many elements are available before resolving the read. This improves upon the current behavior, where reads may resolve with fewer elements than the view can hold.

Get Installed Related Apps API on desktop
The Get Installed Related Apps API (navigator.getInstalledRelatedApps) provides sites access to if their corresponding related applications are installed. Sites are only allowed to use this API if the application has an established association with the web origin.

The API was launched in Chrome 80 for Android. Additional support for web apps on Desktop was enabled in Chrome 140.

Http cookie prefix
In some cases, it's important to distinguish on the server side between cookies set by the server and those set by the client. One such case involves cookies normally always set by the server. However, unexpected code (such as an XSS exploit, a malicious extension, or a commit from a confused developer) might set them on the client. This proposal adds a signal that lets servers make such a distinction. More specifically, it defines the Http and HostHttp prefixes, which ensure a cookie is not set on the client side using script.

Service worker
SharedWorker script inherits controller for blob script URL
The specification states that workers should inherit controllers for the blob URL. However, existing code allows only dedicated workers to inherit the controller; shared workers don't. This fixes Chrome's behavior to align with the specification. The SharedWorkerBlobURLFixEnabled enterprise policy controls this feature.

Add ServiceWorkerStaticRouterTimingInfo
This feature adds timing information for the ServiceWorker Static routing API, exposed in the navigation timing API and resource timing API for developer use. ServiceWorker provides timing information to mark certain points in time.

This feature adds two pieces of Static routing API-relevant timing information:

• RouterEvaluationStart: Time to start matching a request with registered router rules.
• CacheLookupStart: Time to start looking up the cache storage if the source is "cache".
  Additionally, this feature adds two pieces of router source information: the matched router source and the final router source.

Origin trials
Enable incoming call notifications
This feature extends the Notifications API to allow installed PWAs to send incoming call notifications—notifications with call-styled buttons and a ringtone. This extension helps VoIP web apps create more engaging experiences by making it easier for users to recognize and answer calling notifications. Additionally, this feature helps bridge the gap between native and web implementations of apps that have them both.

Crash Reporting key-value API
This feature introduces a new key-value API, tentatively window.crashReport, backed by a per-document map that holds data appended to crash reports.

The data placed in this API's backing map is sent in the CrashReportBody if any renderer process crashes occur on the site. This lets developers debug what specific state in their application might be causing a given crash.

Add the clipboardchange event
The clipboardchange event fires whenever a web app or any other system application changes the system clipboard contents. This allows web apps like remote desktop clients to keep their clipboards synchronized with the system clipboard. It provides an efficient alternative to polling the clipboard with JavaScript for changes.

Enable SharedWorker on Android
The long-standing demand for SharedWorker support on Android stems from several needs expressed by web developers:

Resource sharing and efficiency: Developers aim to share a single WebSocket or Server-Sent Events (SSE) connection across multiple tabs, thereby conserving resources.
Persistent resource management: A requirement to share and persist resources across tabs, particularly for technologies like WASM-based SQLite.
Closing a feature gap: Other major mobile browsers, including Safari on iOS and Firefox on Android, already support SharedWorker, making Chrome on Android the last major browser to address this gap.

Removals
Stop sending Purpose: prefetch header from prefetches and prerenders
Prefetches and prerenders now use the Sec-Purpose header, therefore the legacy Purpose: prefetch header is being removed.

This will be scoped to speculation rules prefetch, speculation rules prerender, <link rel="prefetch"></link>, and Chromium's non-standard

Deprecate special font size rules for H1 within some elements
The HTML spec contains a list of special rules for

tags nested within <article>, <aside>, <nav>, or <section> tags:

These special rules are deprecated, because they cause accessibility issues. Namely, they visually reduce the font size for nested # elements so that they "look" like ## elements, but nothing in the accessibility tree reflects this demotion.