Developer
Tools will load when you run.CSS Validator✓
Parse CSS syntax and download a JSON report. This does not check visual rendering or browser compatibility.
Your result.
How to use CSS Validator
- Choose your CSS, plain text or paste text into the editor.
- Choose your CSS source or paste it into the editor and review the supported parser or engine.
- Run validation and review the CSS JSON report.
Process multiple files
Use a workflow to apply the same settings to each file.
Formats and requirements
- Input formats
- CSS, plain text
- Output
- JSON
- Availability
- Free in your browser and through the CLI
- Files per operation
- 1
- Browser file limit
- 8 MiB per file, 128 MiB total
What to expect
Checks syntax with a local parser. Does not check project types, imports, dependencies or runtime behavior. Markdown accepts ordinary prose; HTML and CSS parsing is not a standards conformance audit.
Do my files leave my device?
No. Thanks to advanced file-processing technology, your files are processed directly on your device, inside your browser. OneKit does not receive your input files or results. Required public processing libraries may download when you first use the tool.
File privacy and local processing →