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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 line-referenced issue list. Load Sample includes a duplicate id so you can see a realistic Error-state result immediately.

This checks structural HTML issues, not full W3C spec conformance — see the official W3C validator for that.

Paste or type your content here…

Paste HTML to check it for structural issues.

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.

HTML Validator

Frequently Asked Questions

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