Check CSS for parse problems and maintainability issues including duplicate selectors, duplicate declarations, empty rules, excessive !important usage, unknown properties, invalid custom-property references, and high selector specificity. The report includes a quality score and code statistics.
Check CSS for duplicate selectors, empty rules, suspicious properties, specificity, custom variables, !important use, and quality issues.
All processing occurs locally in the browser. Review automated findings before using the result in production.
The editor is preloaded with a working CSS Checker example. Change the sample, select an option, and run the tool to compare the input with the generated output and report.
Run the complete or maintainability audit. Repeated selector text is reported with its occurrence count.
The checker identifies empty declarations, malformed blocks, suspicious properties, missing custom variables, and other common causes.
Use the specificity profile and set a warning threshold. Selectors above the threshold are listed.
It checks declarations against a broad built-in property set and marks unknown or suspicious property names.
Yes. It counts custom properties, var() references, media queries, keyframes, selectors, rules, and declarations.
| Module | Details |
|---|---|
| Rules | Selectors and declarations |
| Quality | Duplicates, empty rules, !important |
| Specificity | Configurable threshold |
| Download | .txt report |