Free XML Validator Online
Free XML Validator Online is a free online tool by US AI. Paste any XML document — RSS feeds, sitemaps, configs, SOAP requests — and get instant well-formedness checks with clear error locations. It runs completely in your browser — no signup, no download, nothing is uploaded.
📖 How to use
- Paste your XML into the validator box and press Validate — malformed tags, unclosed elements and attribute errors are listed with line numbers.
- Open the tool with the button above — it loads instantly.
- Fix and re-validate; everything happens on your device, nothing is uploaded anywhere.
✨ Why use this tool?
US AI's free xml validator online is fast, private and 100% free forever. Bookmark this page and share it with anyone who needs it.
❓ Frequently asked questions
What does the XML validator check?
It checks XML well-formedness: matching open and close tags, proper nesting, quoted attributes, and a single root element. Errors are reported with line numbers so you can fix them fast.
Does it validate against an XSD or DTD schema?
No — this is a well-formedness checker. Schema (XSD/DTD) validation is a planned future addition.
Is my XML data uploaded anywhere?
No. Validation runs 100% in your browser — your XML is never sent to a server or stored.
Can I validate RSS feeds or sitemaps?
Yes — paste any XML document, including RSS feeds, Atom feeds, sitemaps, configs and SOAP requests.