Web Platform Baseline brings clarity to information about browser support for web platform features.

Baseline gives you clear information about which web platform features are ready to use in your projects today. When reading an article, or choosing a library for your project, if the features used are all part of Baseline, you can trust the level of browser compatibility.

Baseline was originated by the Chrome team and is now defined by the WebDX Community Group.

Baseline has three stages:

  • Limited availablity: The feature is not available in all the core browsers.
  • Newly available: The feature becomes supported by all of the core browsers, and is therefore interoperable.
  • Widely available: 30 months has passed since the newly interoperable date. The feature can be used by most sites without worrying about support.
  • Chrome (desktop and Android)
  • Edge
  • Firefox (desktop and Android)
  • Safari (macOS and iOS)

Baseline at I/O

Google I/O is here, and there's a bunch of news to share about Baseline and what's new to the web at large. Learn more in this post.
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Baseline and tooling

As Baseline has matured, we've seen that more developers are beginning to integrate it into their development workflows. Learn about the latest tools to integrate Baseline, as well as resources you can use to build your own tools!
The Baseline Netlify extension helps developers to understand which Baseline targets are best supported by users. Learn more in this post on how to use it!
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Learn about the new Baseline support in VS Code.
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Add Baseline to your development linting and packaging tools with browserslist-config-baseline.
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Learn about the Web Platform Dashboard and how you can query its HTTP API to help you build Baseline tools.
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You can now use ESLint to lint CSS and enforce usage of Baseline CSS features in your project! Learn more in this blog post.
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How RUMvision incorporated Baseline information with their RUM data.
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Baseline theory

Adopting Baseline in your projects means there are some considerations you need to make. These materials will help you to answer the hard questions, from polyfilling, tooling, and more.
Learn what Baseline targets are, how to choose one, and how it can help your development experience.
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Knowing when to reach for a polyfill can be a hard decision, but using Baseline features can help you answer this question. Learn more in this guide!
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The Baseline monthly digest

The Baseline monthly digest is a monthly newsletter that highlights what happened each month with Baseline, including new features, community updates, and anything else that fits!
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Baseline targets

When features become part of Baseline in a given year, they're grouped into a feature set—also known as Baseline targets. Here are just a few of the targets you can explore to see what features you can use today.
There are still many browser releases to come in 2025, and as they arrive, they will be part of Baseline 2025. Follow along as we announce new features throughout the year.
Baseline 2025 features
All items that become part of Baseline Newly available in 2024 can be referred to as Baseline 2024. We published a post at the end of 2024 to round up all the features that landed during the year.
Baseline 2024 features
All items that become part of Baseline Newly available in 2023 can be referred to as Baseline 2023. We published a post at the end of 2023 to round up all the features that landed during the year.
Baseline 2023 features
Size container queries became Baseline Newly available in February 2023.
:has() became Baseline Newly available in December 2023.
Subgrid became Baseline Newly available in September 2023.
Nesting became Baseline Newly available in August 2023.
The <search> element became Baseline Newly available in October 2023.
Responsive video became Baseline Newly available in November 2023.
The inert attribute became Baseline Newly available in April 2023.
The Constraint Validation API became Baseline Newly available in March 2023.
:user-valid and :user-invalid became Baseline Newly available in October 2023.
Compression Streams became Baseline Newly available in May 2023.
The Declarative Shadow DOM became Baseline Newly available in February 2024.
Popover became Baseline Newly available in January 2025.

Where to find Baseline

Check the Baseline status of a property on MDN.
Find Baseline on MDN
Check Baseline status on Can I Use to see if a feature is ready for use.
Visit Can I Use
Use Baseline to clarify feature status in your articles and presentations.
Show Baseline status