Biome 2.6.2 Adds Markdown, YAML and SCSS Support and Promotes 59 Nursery Lint Rules to Stable Groups

Overview

The Biome toolchain for JavaScript, TypeScript and web files published version 2.6.2 on October 21, 2026, according to the GitHub release page. The release is listed as a set of minor changes and widens the file types Biome handles: its notes describe added support for Markdown, YAML and SCSS, alongside the promotion of 59 nursery lint rules to stable groups.

The previous Biome release the Herald covered was 2.5.15, which was reported earlier this month.

What Changed

New file types

• Markdown. The release notes say Biome added support for linting and formatting Markdown files, and that the first version of its Markdown parser “has 100% compatibility against CommonMark.” GitHub Flavored Markdown is not yet covered; the notes say “we plan to support them soon.” The parser has opt-in frontmatter parsing and a cjkFriendlyEmphasis option, and the formatter gains a proseWrap option. The notes say the formatter’s compatibility with Prettier is “more than 90% detected by our infrastructure,” and that the linter ships “a few rules inspired by markdownlint.” Code inside fenced blocks, frontmatter and HTML blocks is formatted as an embedded language by default through markdown.formatter.formatEmbeds.
• YAML. The notes list formatting support for both .yaml and .yml files.
• SCSS. The notes say Biome “can now format and lint .scss files, and recognizes .module.scss files as CSS Modules.”

The pull request that enabled Markdown states that the linter and formatter are enabled by default, and acknowledges that “formatting always brings changes to a codebase.” The pull request that enabled SASS says that “due to the current limitations, we can’t support cases like mixins, extend, etc.” and that the documentation was expanded for those cases.

Lint rules

Per the release notes, 59 nursery rules were promoted to stable groups. The notes list promotions into the correctness, suspicious, security, performance, complexity and style groups. The correctness promotions are recommended and carry error severity. Examples named in the notes include useIframeSandbox, promoted to the security group with error severity, and useArraySome, promoted to the complexity group.

Commands and configuration

The same release page lists several tooling additions:

• A biome migrate stylelint command that imports a Stylelint configuration and its ignore settings and maps Stylelint rules to Biome equivalents. Passing --write applies the changes.
• A biome inspect config command that shows resolved configuration values and their origins as human-readable diagnostics.
• Configuration files that can extend other configurations up to ten levels deep.
• A --git flag for biome init, and automatic Git VCS integration when biome init runs inside a Git repository.
• A --profile-type-inference option for lint and check, which tracks the execution time of internal queries and operations.
• Support for distributing named Grit rules, rule presets and configurations through packages that have a manifest file.
• Android (Termux) support in the npm distribution through the @biomejs/cli-android-arm64 and @biomejs/cli-android-x64 packages.

What We Don’t Know

The release notes do not say how many projects have switched on the new formatters, or how the Markdown and SCSS output compares with Prettier on real repositories beyond the stated figure of more than 90% compatibility. The Markdown pull request describes the linter and formatter as enabled by default, and the release notes do not describe an upgrade path beyond the configuration options listed above.