Autoprefixer is a PostCSS plugin and tool that parses CSS and adds vendor prefixes to CSS rules based on browser support data from Can I Use. It helps you write CSS without vendor prefixes and automatically generates the needed prefixed versions for targeted browsers.
Project status
- Actively maintained: Upstream GitHub activity is recent (last push 2026-06-24) and the update stream is continuous through 2026 (e.g., 10.5.1 on 2026-06-23 and 10.5.2 on 2026-06-24), indicating ongoing maintenance.
- Apparent update cadence: Several updates occurred in 2026, with relatively tight spacing in late June (back to back days), then broader gaps (April 2026 for 10.5.0, February 2026 for 10.4.24 to 10.4.27), suggesting an evolving but not daily cadence.
AI summary generated
Recent updates
10.5.2
Autoprefixer 10.5.2 changes how it orders intrinsic stretch-related width fallbacks by reordering the generated vendor values. The release notes claim one ordering change, but the actual code and updated test/README outputs show the opposite ordering for Firefox-related values.
Breaking10.5.1
Release 10.5.1 fixes an issue where grid-area MSIE span values were not reset correctly when a later rule overrides a broader grid area. The code change also adds more robust selector overlap detection to decide when the row and column spans should be adjusted.
10.5.0
Version 10.5.0 primarily adds vendor prefix support for the CSS mask-position-x and mask-position-y properties. The diff also includes build and developer tooling changes (lint/test tooling), plus updates to runtime data dependencies that can change prefixing behavior beyond the single documented feature.
Features10.4.27
Release 10.4.27 primarily updates project metadata and publishing-related tooling. The release notes claim only a removal of the development key from package.json, while the actual diff also shows a dependency version bump for clean-publish.
10.4.26
Release 10.4.26 claims only one change: reduced package size. The diff shows this was implemented via publishing configuration changes, plus updates to dev tooling dependencies and their lockfile resolution.
10.4.25
Version 10.4.25 includes a fix for gradient handling when CSS Custom Properties (CSS variables) are used, specifically addressing broken output in legacy gradient generation. The code changes add a guard to avoid generating the older WebKit gradient form when a gradient value contains var(...).
10.4.24
Release 10.4.24 updates the project version and claims a small Autoprefixer performance improvement. The code diff shows micro-optimizations (replacing Array.concat patterns with push/push spread) plus a patch bump of caniuse-lite used for prefix data.
10.4.23
Release 10.4.23 makes a small dependency cleanup and updates various tooling dependencies and CI actions. While the release notes only mention dependency reduction, the code diff also changes how gradient angle values are normalized.
10.4.22
Release 10.4.22 primarily updates how Autoprefixer determines prefixes for `width: stretch` based on newer Can I Use data. It also bumps `fraction.js` to a newer major version and refreshes dependency metadata used during prefixing.
10.4.21
Release 10.4.21 focuses on correcting how Autoprefixer generates the selector for `:placeholder-shown` when the `-moz-` prefix is involved. The code diff also includes dependency bumps and some internal import reordering, but no other user-facing logic changes are evident from the provided diff.
10.4.20
Release 10.4.20 primarily adjusts autoprefixer’s handling of the `fit-content` prefixing behavior specifically for Firefox. In addition to the documented Firefox fix, the diff shows dependency and tooling updates that can indirectly change prefixing outcomes across other CSS features.
10.4.19
Release 10.4.19 removes the mixed-support warning logic related to using `start` and `end` on flex alignment/justification properties. The code change also eliminates the associated test coverage for those warnings, and updates several tooling and dependency versions (including `caniuse-lite`).