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XML Validator — Check Well-Formedness and Structure

Check XML is well-formed, with the exact line and column of the first error and a document summary.

An XML validator checks that a document is well-formed: every tag closed and correctly nested, exactly one root element, attributes quoted, and reserved characters escaped. This reports the first error with its line and column, and for a valid document summarises the element count, nesting depth, attributes and namespaces.

Runs in your browser
Privacy
Runs entirely in your browser — nothing is uploaded
Cost
Free, unlimited, no sign-up

Frequently asked questions

Does this validate against my XSD schema?

No — browsers have no built-in schema validator, and shipping one would mean a large library for a check most people do not need. This verifies well-formedness, which is the failure that causes almost every "my XML will not parse" problem.

My file looks fine but fails on line 1, column 1. Why?

Almost always a byte-order mark or whitespace before the XML declaration. The `<?xml ...?>` declaration must be the first bytes of the file with nothing whatsoever before it. Saving as "UTF-8 without BOM" fixes it.

How to use the xml validator

  1. 1Enter or paste your xml.
  2. 2Turn "Report namespaces and attributes" on or off as needed.
  3. 3The result appears immediately — copy or download it.

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Put the working xml validator on your own site. It runs in your visitors' browsers exactly as it does here — free, no account, nothing uploaded.

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