HTML Validator

This HTML validator is a structural lint tool - unclosed/mismatched tags, duplicate ids, missing alt/lang, deprecated tags, and suspicious nesting. It does not replace the W3C validator for full spec conformance.

Paste markup and Validate to get a JSON report with line references. Ideal for quick checks before a fuller conformance pass.

Input
Paste or type your content here…
Output
Your result will appear here

Frequently Asked Questions

Is this the W3C validator?
No. Scope is structural checks only - stated clearly on-page.
Are scripts executed?
No. Markup is linted as text, not executed.