Baseline Features audit lands in Lighthouse

Sites that want to track which Baseline features they depend on can now run the Baseline Features audit in Lighthouse. The audit is designed to surface modern web capabilities in your Lighthouse reports and help you identify where your site already takes advantage of them.

Community round-up: Testing and real-world usage

  • Modern Web Guidance against a React app: Ahmad Alfy applied the Modern Web Guidance agentic coding skill to a production React application. His write-up shows how the skill flags outdated patterns and points toward current best practices in a real codebase.
  • Four 2026 APIs worth adopting: Dennis Morello highlights four web platform APIs that reached Baseline in 2026: the Navigation API, container style queries, :open, and Math.sumPrecise(). The post focuses on how these built-in features can replace external dependencies.

Newly available in Baseline

The following features are now supported across all core browser engines and have reached Baseline Newly available status.

Intl.Locale

Internationalization code gets a standard way to work with locale identifiers. The Intl.Locale object parses, manipulates, and queries Unicode locale tags—language, script, and region sub-tags—without hand-rolled string parsing. See the MDN documentation.

Now Widely available

These features have been supported across all major browser engines long enough to be considered Baseline Widely available, so you can use them without polyfills.

Array.fromAsync()

Converting an async iterable into an array is now fully interoperable. Array.fromAsync() behaves like Array.from() but is designed for asynchronous data streams. More details are in the MDN reference.

Image file type and format guide

The MDN guide to image file types and formats has been updated with browser support details across modern image formats, helping you pick an imagery strategy for your site.

rect() CSS function

The rect() basic shape function offers a cleaner way to define rectangular clip paths and offset paths in CSS. You specify inset distances directly from the containing block's edges. Syntax information is available in the MDN documentation.

If you have questions or feedback about Baseline, or if a community post or update was missed for the digest, file an issue on the web-platform-dx/web-features issue tracker.