CSS Validator

Validate CSS code for syntax errors, unclosed rules, invalid selectors, and structural issues with detailed error reporting and statistics.

Drop a .css file here or browse

CSS Code:

Try examples:

Valid CSS Unclosed brace Bad selector Missing semicolon Media query

How It Works

This tool parses your CSS and checks for structural and syntax errors. It validates brace matching, selector syntax, property declarations, at-rule structure, and common mistakes. All processing happens entirely in your browser — no data is sent to any server.

What Gets Checked

Matching curly braces { }
Valid selector syntax (no empty selectors, proper combinators)
Property declarations end with semicolons
No empty rule blocks
Matching parentheses and brackets
Proper at-rule structure (@media, @keyframes, etc.)
Unclosed strings and comments
Common typos and invalid patterns

CSS Syntax Rules

Selectors are followed by a declaration block: selector { ... }
Declarations use the form: property: value;
Each declaration ends with a semicolon
At-rules start with @: @media, @import, @keyframes
Comments use /* ... */ syntax
Strings use single or double quotes

Common Errors

Error	Example	Fix
Unclosed brace	`.box { color: red;`	`.box { color: red; }`
Missing semicolon	`color: red font-size: 14px`	`color: red; font-size: 14px;`
Empty selector	`{ color: red; }`	`p { color: red; }`
Unclosed comment	`/* comment`	`/* comment */`
Unclosed string	`content: "hello;`	`content: "hello";`

Tip: Need to format or beautify your CSS? Try the CSS Formatter for pretty-printing and minification.

Embed This Util

You can embed this util on your own site as a widget. Adding ?embed=1 to the URL loads a compact version with just the tool itself; no header, menu, or documentation. Paste this snippet into your HTML:

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