Is this HTML validator free?
Yes. This HTML validator is free to use with no sign-up and no limit on how many pages you check.
Does it upload my HTML to a server?
No. The validation runs entirely in your browser, so the HTML you paste stays private on your device and is never uploaded.
Is this a full standards-complete validator?
No. It is a practical checker for common title, meta description, canonical, anchor, and structure issues, not an official conformance service.
Does it fetch live URLs?
No. This version validates only the HTML you paste. It does not crawl or fetch pages from the web.
Can I check staging pages?
Yes. Because everything runs in your browser and nothing is uploaded, you can safely check markup from staging or unpublished pages.
Is this the same as the W3C validator?
No, and it does not try to be. The W3C service checks your markup against the HTML specification: element nesting, content models, attribute names and values, and required structure, and it reports errors with line numbers. This page runs nine practical checks on titles, descriptions, canonicals, anchors, and content structure. Use validator.w3.org when you need conformance, and use this when you want a fast content and metadata sanity check.
Will it tell me if I forgot a closing tag?
No, and it is worth understanding why. The markup is parsed by the browser's HTML parser, which is required by the specification to repair broken input rather than reject it. A missing </p> or a stray <div> is silently closed for you, and the resulting tree looks perfectly healthy. There is a parser-error check in the code, but it only triggers on XML parsing, so in text/html mode it never fires.
Why does it say my title is missing when the tag is right there?
Almost always because you pasted a fragment. The lookup runs against document.head, and a <title> or <meta> pasted without a <head> wrapper is placed in the body by the HTML parser, where the check cannot see it. Paste the whole document, or at least the complete <head>...</head> block, and the warning goes away.
What does "Canonical is not absolute" mean?
The canonical link exists but does not start with http:// or https://. Search engines generally handle a relative canonical, but it is fragile: it resolves against the current page, so a change of path or a protocol mismatch can silently point it somewhere you did not intend. Use the full absolute URL, including the scheme and the host you want indexed.
Does "No obvious practical issues found" mean my HTML is valid?
No. It means none of the nine checks fired. Your markup can still be unbalanced, use invented attributes, nest a <div> inside a <p>, duplicate an id, or omit every alt attribute, and this page will report nothing. The message is deliberately worded as "no obvious practical issues" rather than as a pass.
Is my HTML uploaded?
No. The document is parsed and the checks run in your browser, which is why the tool cannot fetch a URL or verify that any link or canonical actually resolves.