Biome 2.5.13

Biome 2.5.13 was published to npm on September 11, 2026 as the latest patch in the 2.5 series. As a patch release it focuses on lint rule additions and correctness fixes rather than new platform support.

New Nursery Rule: useLayeredStyles

The release adds a new nursery rule, useLayeredStyles, which flags CSS that can be restructured into layered style groups. As a nursery rule it ships opt-in until the Biome maintainers graduate it to the recommended set.

Formatting and Parser Fixes

Several fixes land across the HTML and CSS formatters. Comment placement is handled more carefully inside functional pseudo-classes and along declaration/value boundaries, so running the formatter stops moving your comments to awkward positions.

Lint Corrections

A batch of lint fixes tighten behaviour for Svelte, Vue and WebAssembly contexts. Cases that previously produced false positives around template globals, expression parsing and GritQL patterns are resolved in 2.5.13.

Upgrading

Biome 2.5.13 is a drop-in patch. Update via your package manager (for example npm i -D @biomejs/biome@latest) and rerun biome check --write to validate against the latest rules.