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What Is Google Baseline and Why Does It Matter?

Interoperability across browser vendors, explained.
Daine Mawer||3 min read|654 words

The short answer

Baseline is Google's cross-vendor scorecard for web features. It tells you whether something is stable across Chrome, Firefox, Safari, and Edge without checking each vendor's docs separately. A feature is either "Newly available" (just landed everywhere) or "Widely available" (stable for 30 months or more), so you know at a glance whether it's safe to ship without a fallback.

For years, checking caniuse.com (opens in a new tab) was the default way to figure out whether a feature was safe to use, whether for backward compatibility or to check if modern browsers had caught up to a newer spec.

In 2023, Google introduced Baseline (opens in a new tab). It's a way to check whether a feature or API is stable enough for production, aimed at making cross-browser support easier to reason about at a glance.

Why Baseline exists

Browsers update monthly, more people are contributing to specs than ever, and the dialogue between vendors (Safari, Firefox, Chrome, Edge) is more open than it used to be. That combination makes it genuinely hard to track which new features are actually stable everywhere. Baseline exists to make that easier.

As new features land in browser engines, engineers still need time to ramp up, refactor, or plan a rollout. Google has acknowledged it's partly responsible for the pace problem here, since Chrome is often first to ship cutting-edge features. That's part of why the Chrome team built web.dev (opens in a new tab) and developer.chrome.com (opens in a new tab), and Baseline has pushed further documentation and interoperability-focused conferences since.

New features mean new documentation too. Google has put real effort into keeping MDN current as newer technologies land in Chrome.

Closing the vendor gap

The core problem engineers deal with is inconsistent feature behaviour across browser engines. It's a genuine pain point, and one that often demands its own planning and workarounds just to route around a specific engine's gaps.

For the last few years, Interop 2022 (opens in a new tab) and Interop 2023 (opens in a new tab) have been the community effort to close that gap and push toward a more consistent web.

What is Baseline?

Baseline is a status flag: it tells you whether a feature is fully stable across the major browser vendors, checked against each vendor's most recent two versions. It gives engineers one place to check instead of cross-referencing several.

How Baseline works

You can check Baseline status directly on MDN (opens in a new tab), web.dev (opens in a new tab), and caniuse.com (opens in a new tab).

Baseline also tracks what became stable year over year. Baseline 2023 (opens in a new tab), for example, covers everything that reached that bar during the year.

Baseline uses two labels:

  • Newly available: the feature just reached support across all four major engines. It works everywhere, but hasn't been around long enough to be considered a safe default without checking your specific browser support targets.
  • Widely available: the feature has been supported across all four for 30 months or more. At this point it's generally safe to use without a fallback or polyfill.

The vendors Baseline considers:

Effect on engineering teams

The biggest win for teams is cutting out the guesswork before adopting a new feature. Say a frontend engineer wants to use CSS Grid's subgrid (opens in a new tab) feature. Baseline gives a fast, confident answer on support instead of a research task.

Subgrid lets you define a grid inside a grid for finer layout control. caniuse.com (opens in a new tab) puts global usage at 87.42%, which sounds decent, but doesn't tell you which vendors support it, partially support it, or don't. That's where Baseline fills the gap: caniuse now shows a Baseline badge marking subgrid as "newly available across major browsers." MDN's subgrid docs carry the same badge, and the web.dev writeup (opens in a new tab) confirms it landed in Baseline in 2023. Three sources, one consistent answer.

A word on evergreen browsers

This doesn't get talked about enough. For most users, manually updating a browser is a thing of the past. Chrome, Firefox, and Edge auto-update. Safari is the outlier, still requiring a manual update or an annual OS upgrade.

Even so, more users than ever are running the latest browser version. Graceful degradation still matters, but it's less of a hard requirement now and more of an extra layer of safety.

Useful links

Takeaways

  1. Baseline replaces piecing together support info from caniuse.com, MDN, and each vendor's own release notes with one status per feature.
  2. "Newly available" means a feature just reached all four major engines. "Widely available" means it's been stable for at least 30 months, generally safe to use without a fallback.
  3. The four vendors Baseline tracks are Safari, Firefox, Chrome, and Edge, on their two most recent versions each.
  4. Evergreen auto-updating browsers, everything except Safari, which still needs a manual update, mean most users are already on a version that supports Baseline-flagged features.

Questions

What's the difference between Newly available and Widely available in Baseline?

Newly available means a feature just became supported across all four major browser engines. Widely available means it's been supported for 30 months or more, generally considered safe to use without a fallback or polyfill.

Which browsers does Baseline track?

Safari, Firefox, Chrome, and Edge, specifically their two most recent versions. That's the same set of vendors behind the Interop project.

Where can I check a feature's Baseline status?

MDN, web.dev, and caniuse.com all display Baseline badges directly on feature pages now, so a separate tool usually isn't needed.