FreeDev Tools

CSS Validator

Check CSS syntax — unbalanced braces, missing colons and semicolons, bad property names.

Runs locally in your browser. Your input is not uploaded.

How to Use

  1. 1

    Paste your CSS

    Whole stylesheets or single rules.

  2. 2

    Read the issues

    Brace, colon, and property problems with line numbers.

  3. 3

    Fix silent failures

    Structural errors explain rules that mysteriously don't apply.

Frequently Asked Questions

Unbalanced braces (with line numbers), unclosed comments, declarations missing a colon, empty values, and malformed property names — the structural errors that silently kill whole rule blocks.

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