Baseline 2024: A Year of Progress for Web Platform Interoperability
In 2024, the Baseline project moved closer to its goal of giving developers a reliable way to know when web platform features are ready to use across browsers. The core dataset that powers Baseline is now mostly complete, and the project added several practical tools. This review covers the milestones from the past year.
How Baseline defines web feature readiness
Baseline labels web features that are supported by all core browsers on both desktop and mobile. This makes it easy to trust browser compatibility when the features you use are part of Baseline. The Baseline site at web-platform-dx.github.io/web-features/ has details on the available labels and how a feature earns a Baseline status.
The state of the web-features dataset
The web-features project is the shared catalog that defines groups and descriptions for features and records Baseline support data. This year saw the dataset reach 81% completion of mapped feature keys, now consumable via the web-features package on npm. This dataset acts as the source of truth for all Baseline statuses.
New tools and resources launched this year
Web Platform Status dashboard
The Web Platform Status dashboard is a new resource backed by web-features data that shows feature implementation progress across browsers. Since its backbone is nearly complete, the dashboard can trend features with better reliability. You can track individual features or filter whole snapshots, such as Baseline 2024. It complements existing compatibility tools like Can I Use and MDN's data. Since the launch, the team added more search filters: group: for grouping and snapshot: for ECMAScript releases, for example snapshot:ecmascript-2023 to see ES2023 features in one view.
The <baseline-status> web component
To make it easier to show Baseline status on your own sites, the <baseline-status> component is ready for use anywhere you mention a feature. It is available to install from npm.
<baseline-status> widget.Official site, logos, and community listing
Baseline, owned by the W3C WebDX Community Group, now has an official project page. Projects that adopt Baseline, whether in writing, talks, or tools, can add themselves to the Baseline in the wild page via Pull Request. For any visual use, check the name and logo usage guidelines; the logos carry a license that permits you to record the status of a web feature next to your content.
Interop 2024 accelerated features
As a result of the Interop project, cross-browser efforts push targeted features into more browsers and speed up the moment they become Newly available. Notable 2024 additions that crossed this threshold include Declarative Shadow DOM, font-size-adjust, requestVideoFrameCallback, and text-wrap: balance.
Baseline adoption beyond the core team
Insights from RUM Archive
The RUM Archive Insights page is the first outside tool to integrate Baseline. Developers can see how their audience falls across Baseline years for each feature, drawn from real user measurements. That data can help teams decide on an appropriate Baseline year target instead of always aiming for Widely available.
#thisisbaseline video series
In 2024, the team also published short videos introducing newly available features under its This Is Baseline series. Topics range from new Set methods to the Screen Wake Lock API and CSS subgrid, each under 60 seconds. The full set of videos is available on YouTube.
Community outreach
Baseline maintainers spent the year at conferences to field questions from developers. Sessions from 2024 include Rachel Andrew at FITC Web Unleashed in October, Pete LePage at connect.tech, and Mariko Kosaka at JSNation in November.
Feature highlights from the Baseline 2024 release
@property for advanced CSS custom properties
CSS custom properties themselves have been available for a while, but support for the @property rule meant you can now set their type, default value, and inheritance. All core browsers shipped this by July 2024, letting custom properties behave in even more reliable ways within styling systems.
Set operations go functional
JavaScript's Set object has supported collecting unique values since ES2015. The new intersection and union methods (along with a few others) let developers perform mathematical operations on Sets natively and are now in all core browsers.
AVIF image support completes
AVIF is now Baseline Newly available across all core browsers. The format offers generally better compression than existing image types, making it a valuable addition for developers concerned about file size and performance. It joined the list in January 2024.
More covered in the full feature list
These highlights are only a few. The whole list of features that joined Baseline this year is published on web.dev.
Acknowledgments for open collaboration
Baseline evolved from a definition announced in May 2022 into an engine that powers dashboards, widgets, and community use cases. Credit goes to the individual contributors to the dataset—Victor Allen, Dietrich Ayala, Daniel Beck, Patrick Brosset, Sondra Eby, Adriana Jara, Mariko Kosaka, Pete LePage, Florian Scholz, James Stuckey Weber, and queengooborg (Vinyl)—and to the widget team of Ewa Gasperowicz and the Chrome DevRel team. The dashboard authors are Panos Astithas, Kyle Ju, James Scott, Daniel Smith, and Jason Xu. The broader Google Baseline team is Aaron Abbarno, Rachel Andrew, Tony Conway, Philip Jägenstedt, Adriana Jara, Mariko Kosaka, Pete LePage, Nandu Nair, Ali Spivak, and Kadir Topal. Special thanks go to collaborators at CanIUse, MDN, RUM Archive, and the wider group of organizations supporting the Interop project.
