Published: September 16, 2025
Browserslist is a utility that tells build toolchains how to modify source code for a specified set of browsers. Browserslist relies on a query syntax that specifies exact versions of browsers, relative queries such as last 2 years, and even usage-based queries like > 0.5%. It's used by other popular tools such as Babel and PostCSS. Chances are, if you use any kind of bundler or transformer, you're using Browserslist.
Due to the popularity of browserslist, the WebDX CG maintained a third-party package to create a browserslist config, named, browserslist-config-baseline. However, the browserslist team has now included a set of Baseline queries in the product, sothis package is no longer necessary to take advantage of Baseline in your toolchains. You can now use Baseline in any toolchain that uses Browserslist!
Baseline queries available in Browserslist
When adopting a Baseline target, you have three options:
- Baseline Widely available, which includes features in browsers that have been interoperable for 30 months or more.
- Baseline Newly available, which includes features that have been interoperable for 30 months or less.
- Baseline years, which target a specific feature set by year. This means that any features available that year and in years past are available to use.
None of these targets are the default in Browserslist. To use Baseline in your project, specify one of these targets by using the following queries in your Browserslist configuration, respectively:
baseline widely available- You can also target browsers containing Widely available features for a specific date:
baseline widely available on 2024-06-06.
- You can also target browsers containing Widely available features for a specific date:
baseline newly availablebaseline 2021. This example targets the 2021 feature set, but you can specify any year betweenbaseline 2015up to the current year.
These queries can be used anywhere in your project where you have a Browserslist config. For example, a .browserslistrc file, package.json, or anywhere else you configure Browserslist. See the Baseline tooling demos for examples of Browserslist queries that make use of this new Baseline syntax. Be sure to experiment with some of the queries and see how it affects the output of your production source code. If you need guidance on which target to use, read How to choose your Baseline target.
This is a big development in the tooling space for Baseline, and we're grateful to the Browserslist team for their collaboration with the WebDX Community Group to land this. Particularly with the moving targets such as baseline widely available that evolve to include an increasing number of qualifying features over time, we think this will be a very useful developer tool!