# Google Chrome 139

- Product: Google Chrome (https://whatsnew.fyi/product/google-chrome)
- Vendor: Google
- Date: 2025-08-05
- Version: 139
- Original notes: https://developer.chrome.com/release-notes/139
- Permalink: https://whatsnew.fyi/product/google-chrome/releases/139

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

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- **added** — Support font-feature-settings descriptor in @font-face rule with string-based syntax as defined in CSS Fonts Level 4
- **added** — Add CSS custom functions that return values based on other custom properties, parameters, and conditionals
- **added** — Enable corner-shape styling to express corner shape and curvature as a superellipse, allowing squircles, notches, and scoops
- **added** — Support async attribute for SVG <script> element to allow asynchronous script execution
- **added** — Add request-close invoker command for declarative control of dialog closure
- **added** — Expose new mechanisms in WebXR depth sensing to customize behavior and improve performance, including requesting raw or smooth depth buffers and non-aligned depth buffers
- **added** — Add 3D texture support for BC and ASTC compressed formats in WebGPU
- **added** — Add securePaymentConfirmationAvailability JavaScript API to check if Secure Payment Confirmation feature is available
- **added** — Add Secure Payment Confirmation Browser Bound Keys with additional cryptographic signature over assertions and credential creation
- **added** — Add font-width property and descriptor, and make font-stretch a legacy alias
- **changed** — Short-circuit var() and attr() functions to evaluate without looking for cycles in fallback when fallback is not taken
- **changed** — Allow active transitions to continue running when transition property is set to none, making Chrome consistent with Safari and Firefox
- **changed** — Change scroll anchoring algorithm to select the candidate as the scope or root of regular anchor selection instead of as the priority candidate
- **changed** — Relax validation of JavaScript DOM APIs to match the HTML parser and allow more characters in element and attribute names

Stable release date: August 5th, 2025
Unless otherwise noted, the following changes apply to Chrome 139 stable channel release for Android, ChromeOS, Linux, macOS, and Windows.
##### CSS and UI
###### Short-circuiting var() and attr()
When the fallback is not taken, var() and attr() functions evaluate without looking for cycles in that fallback.
ChromeStatus.com entry
###### Support font-feature-settings descriptor in @font-face rule
This feature supports the string-based syntax for font-feature-settings as defined in CSS Fonts Level 4. Invalid or unrecognized feature tags will be ignored per specification. No binary or non-standard forms are supported.
As OpenType fonts become more widely adopted, this enhancement will improve typographic control, reduce redundancy, and support a more scalable, modern approach to web design.
Tracking bug #40398871 | ChromeStatus.com entry | Spec
###### CSS custom functions
Custom functions are similar to custom properties, but instead of returning a single, fixed value, they return values based on other custom properties, parameters, and conditionals.
Tracking bug #325504770 | ChromeStatus.com entry | Spec
###### Continue running transitions when switching to initial transition value
When the transition related properties change, they are only supposed to affect newly started transitions. This means that if you change the transition properties, unless you also change the properties which have active transition animations, those transition animations will continue with the previously specified duration and easing.
Chrome incorrectly canceled transitions when the transition property was set to none, even though it doesn't cancel them if you only change the transition-duration. This change makes Chrome consistent with Safari and Firefox, allowing active transitions to continue running, until their property value changes triggering a new transition update.
ChromeStatus.com entry | Spec
###### Corner shaping (corner-shape, superellipse, squircle)
Enable styling corners, on top of the existing border-radius, by expressing the shape and curvature of the corner as a superellipse.
This allows shapes like squircles, notches, and scoops, and animating between them.
Tracking bug #393145930 | ChromeStatus.com entry | Spec
###### Add font-width property and descriptor and make font-stretch a legacy alias
###### Support async attribute for SVG <script> element
The SVGScriptElement interface in SVG 2.0 introduces the async attribute, similar to the HTMLScriptElement. This attribute allows scripts to be executed asynchronously, improving the performance and responsiveness of web applications that use SVG.
Tracking bug #40067618 | ChromeStatus.com entry | Spec
###### The request-close invoker command
Dialog elements can be closed through a variety of mechanisms, sometimes developers want to have the ability to prevent closure. To achieve this dialogs fire a cancel event. Originally this was only fired via a close request (for example, an ESC key press), recently a requestClose() JavaScript function was added which also fires the cancel event.
The request-close command brings that new ability to the declarative invoker commands API.
Tracking bug #400647849 | ChromeStatus.com entry | Spec
###### Scroll anchoring priority candidate fix
Changes the scroll anchoring algorithm. Instead of selecting the priority candidate as the anchor, choose the candidate as the scope or root of the regular anchor selection algorithm which will select the deepest onscreen element as the anchor.
ChromeStatus.com entry
##### Device
###### WebXR depth sensing performance improvements
Exposes several new mechanisms to customize the behavior of the depth sensing feature within a WebXR session, with the goal of improving the performance of the generation or consumption of the depth buffer.
The key mechanisms exposed are: the ability to request the raw or smooth depth buffer, the ability to request that the runtime stop or resume providin

_[Truncated at 4000 characters — full notes: https://developer.chrome.com/release-notes/139]_