Skip to content
🩺

CSS Validator

Check a stylesheet for syntax errors, unknown properties, duplicate declarations and other problems that browsers silently ignore.

Errors

0

Warnings

0

Suggestions

0

This validator reads a small hand-checked list of standard properties, so it catches misspellings rather than enforcing the full specification. A clean result is not a guarantee that every browser will accept the file. Custom properties (--my-var) and unknown at-rules are reported as warnings, not errors.

More in CSS Tools

View all →
CSS Gradient Generator Create beautiful CSS gradients CSS Minifier Strip whitespace and comments Box Shadow Generator Visual CSS box shadow builder CSS Beautifier Reformat messy CSS to be readable Text Shadow Generator Visual CSS text-shadow builder CSS Specificity Checker See which selector wins

What Is CSS Validator?

The CSS Validator scans your stylesheet for errors, warnings, and informational notes, then summarizes everything in a clear report. Filter down to problems only, fix typos, unknown properties, and brace mismatches, and re-validate until the sheet is clean.

Who Uses the CSS Validator?

Developers and students use it to catch typos, validate generated CSS, and learn correct property usage.

How to Use the CSS Validator

  1. Paste your CSS into the validator.
  2. Read the summary of errors, warnings, and notes.
  3. Toggle problems-only to focus on what breaks.
  4. Fix each issue and re-validate.

Why Choose Our CSS Validator?

  • Errors, warnings, and infos separated by severity
  • Problems-only filter for focused debugging
  • Plain-language findings you can act on

Try the CSS Validator above — it is free, fast, and works on any device. Bookmark this page to return whenever you need it.