Published: March 31, 2025
Another month has gone by and since the last Baseline monthly digest, a lot has happened! In this edition, we'll recap some posts we've published here on web.dev, some Baseline Newly available features that have landed, and some updates to tooling in the community.
ESLint 0.6.0 has been released
Recently, we posted about ESLint launching support for linting CSS. Part of this launch included a new ESLint rule—require-baseline—for linting the CSS features you use in your project, and whether they reach a specific Baseline threshold.
Recently, ESLint launched version 0.6.0 of the @eslint/css package, which includes an important new update that renames the require-baseline rule to use-baseline. While this update is seemingly a small one, it improves on the readability of the rule. There are also some other important features and bug fixes in this release, such as the added capability of the use-baseline rule to lint nested CSS blocks. If you're using a prior version of @eslint/css, check out this update!
How to query the Web Platform Dashboard
Earlier this month, we published a post about querying the Web Platform Dashboard. This dashboard can be queried on its frontend, as well as through an HTTP API. This can be potentially useful for Baseline tooling, as you can query the API to find features that have reached a specific Baseline threshold.
This API can be useful for tooling where you need to quickly get information about specific features. For example, you could use this type of tooling to write a script that tells you on some interval which features have become recently Baseline Newly available or Widely available. If this sounds like something useful to you, give the post a read!
How to think about Baseline and polyfills
Baseline's mission is to bring clarity to which features you can safely use—but even with that added clarity, you still have to think about how to adopt features in a way that makes sense for your web applications. Polyfills are a big part of that process. Baseline doesn't consider polyfills in whether features are Newly or Widely available, and it doesn't try to tell you whether to use them. That decision is specific to your application, but it's an important consideration!
Recently, we published a post on how to think about Baseline and polyfills, and we think it provides a helpful framework for how to think about using them. The hope with features that become Baseline Newly or Widely available is that polyfills become less of a necessity. There's no doubt that polyfills are useful tools in your development toolbox, but they have disadvantages—they can have a negative impact on your website's performance, and in some cases, there can even be accessibility concerns. Hopefully this guide helps you to navigate this tricky question!
contenteditable="plaintext-only" is now Baseline Newly available
The contenteditable attribute on an HTML element allows the user to change its contents as though it were a text field. This means, for example, you could place the attribute on a <p> element and the user can interact with it like a <textarea>. In some use cases, using contenteditable offers advantages over typical form elements.
However, users paste stuff into editable elements, and the stuff they paste can contain rich text formatting, which can provide a frustrating experience for users who just want to paste unformatted text into a field. The contenteditable="plaintext-only" attribute/value combination prevents this from happening, and it recently became Baseline Newly available. To find out more, read the announcement post, and learn how you can provide a better editing experience for users who just want to paste text into things without all of the fluff.
Intl.DurationFormat is now Baseline Newly available
You've probably been on a website at some point in your life and have seen a bit of text that communicates the duration of time until, or after some event, often in a string like "2 days, 6 hours, 3 minutes". This data is useful for communicating any number of timely things, but it's often provided by a library. On top of that, you might want to output this information in multiple languages.
Enter Intl.DurationFormat, an internationalization feature that has recently become Baseline Newly available. With the Intl.DurationFormat class, you can pass an object to its constructor containing the units of time you want formatted into a string, and in almost any language you can think of:
const duration = {
years: 1,
hours: 20,
minutes: 15,
seconds: 35
};
// English output: '1 year, 20 hours, 15 minutes, 35 seconds'
new Intl.DurationFormat('en', { style: 'long' }).format(duration);
// German output: '1 Jahr, 20 Stunden, 15 Minuten und 35 Sekunden'
new Intl.DurationFormat('de', { style: 'long' }).format(duration);
// Spanish output: '1 año, 20 horas, 15 minutos y 35 segundos'
new Intl.DurationFormat('es', { style: 'long' }).format(duration);
The exciting part of this is that if your application relies on a library to format strings like this, you'll soon be able to do so without a library, saving kilobytes for your users. For more information, read the announcement post about Intl.DurationFormat, and learn how you can take advantage of this handy new feature!
Baseline at W3C Breakouts Day 2025
Recently, The W3C held the 2025 edition of its Breakouts Day, where members presented on various topics, and a useful session on Baseline was offered on the 26th of March.
If you're new to Baseline, this session does a great job of giving a quick overview. It covers the basics of Baseline such as the Newly and Widely available concepts, but also goes into how those definitions are determined by data, starting from browser-compat-data, working up to the web-features data that helps us to figure out which features are at what Baseline threshold.
If you missed this session, don't worry! Slides from the session are already available, so give them a look if your curiosity gets the better of you.
That's a wrap!
This edition of the monthly digest doesn't just mark the end of the month, but also the quarter. If you've missed previous versions of the digest, check out the January and February editions to get up to speed on all that's happened with Baseline in the first quarter of this year. As usual, let us know if we missed anything Baseline-related, and we'll make sure it gets captured in a future edition. See you in a month!