Chrome 157 Release Notes

The anchors-valid value was implemented as part of https://crbug.com/329703412 but subsequently reverted, due to spec questions about the exact definition of the value. Since that time, the value has been renamed to anchor-valid (see https://chromestatus.com/feature/5136123851571200) and also better defined to be clear that only the default anchor matters, resolving a lot of ambiguity, and making this value shippable.

Adds a <string> value to the text-overflow property.

This allows web authors to specify a custom string (e.g., "(more)") to indicate that text has been clipped. This provides more design flexibility and can be used to create more user-friendly and context-aware overflow indicators.

The CSSWG resolved to rename anchors-valid --> anchor-valid [1] and anchors-visible --> anchor-visible [2]. To accomplish this, we'll rename the properties to the singular variants, and add aliases from the plural versions to the singular versions. At a later date, we will remove the plural variants. This chromestatus is only about shipping the new versions, and deprecating the old ones (but not removing them).

[1] https://github.com/w3c/csswg-drafts/issues/10201#issuecomment-4180411971 [2] https://github.com/w3c/csswg-drafts/issues/10201#issuecomment-4390233490

SVG documents loaded through <object> or <embed> are sized and positioned inside the element's content box according to the CSS object-fit and object-position properties, the same way <img> content is.

Previously Chrome ignored both properties for embedded SVG documents and always stretched the document viewport to the whole content box.

According to the URL Standard specification, URL hosts cannot contain the space character, but currently URL parsing in Chromium allows spaces in the host. This causes Chromium to fail several tests included in the Interop2024 HTTPS URLs for WebSocket and URL focus areas. To bring Chromium into spec compliance, we would like to remove spaces from URL hosts altogether, but a difficulty with this is that they are used in the host part in Windows file:// URLs. For more details, see this Github discussion.

Chrome is changing its behavior to allow pages with active WebSocket connections to enter the Back/Forward Cache. To achieve this, active WebSockets are now disconnected when a page is cached. Previously, active WebSocket connections prevented pages from entering BFCache.

To revert to the previous behavior (preventing pages with active WebSockets from entering BFCache), we've provided a BackForwardCacheForWebSocketsAllowed policy. Admins can set this policy to Disabled , which will prevent breakage in legacy apps that lack WebSocket reconnection logic.

For more information on BFCache, see Test back/forward cache.

ProgressEvent is available in service workers, allowing developers to construct progress events with lengthComputable, loaded, and total attributes. This aligns service workers with other worker contexts and the XMLHttpRequest Standard.

Exposes the LanguageDetector JavaScript Web API on Chrome for Android (Clank). This allows web applications to detect text languages locally on mobile devices using fast, privacy-preserving, and offline-capable on-device machine learning models and not rely on cloud endpoints.

Prerenders cross-origin iframes with an opt-in response header.

Browsers will now prerender all cross-origin frames if the top-level frame's HTTP response includes the Supports-Loading-Mode: prerender-cross-origin-frames.

BluetoothRemoteGATTServer inherits from EventTarget, exposing the standard addEventListener(), removeEventListener(), and dispatchEvent() methods. This enables connection-level events to be dispatched directly on the GATT server.

Expand the TextMetrics Canvas API to support selection rectangles, bounding box queries, and glyph cluster-based operations.

This new functionality should enable complex text editing applications with accurate selection, caret positioning, and hit testing. Additionally, cluster-based rendering facilitates sophisticated text effects such as independent character animations and styling.

Allows the use of 64-bit atomic minimum and maximum operations on atomic<vec2u> in WGSL.

This provides WebGPU shader authors with a way to implement certain algorithms that use 64-bit atomics without requiring full support for 64-bit integers.

Expose multiple HTML setting methods that provide a coherent story for dynamically inserting markup into an existing document.

• Positional methods (before/after/append/prepend/replaceWith) that take HTML as argument, effectively replacing insertAdjacentHTML.
• Streaming methods (stream{Append}HTML{Unsafe}) which return a WritableStream
• Passing {runScripts} as part of SetHTMLUnsafeOptions, mimicking createContextualFragment behavior.
• Supporting createParserOptions in trusted types, allowing trusted types to override scripting mode and sanitizer.

WebTransport.draining is a promise that resolves when the server indicates that the WebTransport session will be gracefully retired. Applications can use this signal to establish a replacement session while existing streams and the current session remain usable.