What is HTML Validator?
An HTML Validator checks your HTML for syntax errors, unclosed tags, malformed attributes, and structure issues. It helps ensure your markup follows standards and works correctly across browsers.
Validation catches problems before they cause layout or rendering issues. Our validator provides clear error messages, line numbers, and guidance for fixing issues.
How to Use HTML Validator
- Paste or upload HTML: Paste your HTML or upload an .html/.htm file.
- Validate: The tool automatically validates and shows errors or a Valid HTML badge.
- Fix errors: Use the error messages and line numbers to correct your markup.
No signup required. Works on desktop and mobile.
Frequently Asked Questions
What does HTML validation check?
It checks syntax, tag matching, attribute validity, and structure. It reports unclosed tags, invalid nesting, and malformed markup.
Does validation fix errors automatically?
No. It reports errors; you fix them. Some validators offer auto-fix; ours focuses on clear reporting.
Why should I validate HTML?
Valid HTML renders consistently across browsers, improves accessibility, and avoids subtle bugs.