# What changed in stylelint-csstree-validator

> 18 changes in stylelint-csstree-validator 2 to 4 from its official release notes, upgrade guides and advisories: 7 breaking, 1 deprecations, 3 new APIs and options. Each one cited. Sources checked 2026-10-31. HTML: https://unstale.sh/npm/stylelint-csstree-validator/

To see which of these apply to a repository, run `npx @unstale/cli init` in it.

## stylelint-csstree-validator 4

### Breaking changes

- Node.js versions below 18.0 are no longer supported. (4.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v4.0.0)
- Support was migrated to stylelint 16.x–17.x. (4.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v4.0.0)
- Support for stylelint 15.x and below was dropped. (4.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v4.0.0)

## stylelint-csstree-validator 3

### Breaking changes

- Support for Node.js versions below 14.13 was dropped. (3.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v3.0.0)

### Tooling

- Added support for stylelint 15. (3.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v3.0.0)

## stylelint-csstree-validator 2

### Breaking changes

- At-rule names, preludes, and descriptors are now validated. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Use `ignoreProperties` in place of the renamed `ignore` option. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Supported Node.js versions are now `^12.20.0`, `^14.13.0`, and `>=15.0.0`. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)

### Deprecations

- The option still works but now causes a deprecation warning; use `ignoreProperties` instead. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)

### New APIs and options

- Extend or alter the at-rule syntax definition dictionary, or disable at-rule validation by passing false. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Specify at-rule names that should not be validated. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Specify syntax extensions such as Sass or Less; CSS is validated by default. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)

### Behavior and default changes

- Mismatch error details now include a column. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)

### Tooling

- The package is converted to ES modules while continuing to support CommonJS as a dual module. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Adds support for Stylelint 14.0. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)

### Fixes and other changes

- The option now applies to parse errors as well. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Values containing Less or Sass namespaces are ignored instead of causing a failure. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)
- Declarations with a Less variable reference are now ignored instead of causing a failure. (2.0.0) — [release notes](https://github.com/csstree/stylelint-validator/releases/tag/v2.0.0)