Free XML Validator
Get a definitive verdict on your XML: well-formed or not. Paste any XML and this free validator checks it with the browser’s native parser — reporting the exact error when it fails and a structural summary when it passes.
Well-formed XML
Invalid XML
How to Use the XML Validator
- Paste the XML you want to check.
- Click Validate XML for an instant verdict.
- Green means well-formed — plus element and attribute counts.
- Red means invalid — read the parser message, fix, and re-validate.
Features
Validation uses DOMParser — the same strictness real XML toolchains apply — so there are no false passes on sloppy markup. Failures surface the parser’s message with line and column details; successes report the root element, total element count, attribute count, and document size.
Benefits & Use Cases
Integrators verify vendor feeds and SOAP payloads before they hit production parsers; developers check config files and sitemaps; anyone hand-editing XML gets instant feedback. Catching a mismatched tag here beats debugging a failed import later.
Tips
The most common failures are unescaped & in text, mismatched tags, and multiple root elements. If the error mentions a line number, look just before it — parsers report where they gave up, not always where the mistake is.
Frequently Asked Questions
What does “well-formed” mean?
That the XML follows basic syntax rules: one root element, properly nested and closed tags, quoted attributes, and escaped special characters. Well-formedness is required before any XML can be processed — it is separate from schema validity.
What is the difference between well-formed and valid XML?
Well-formed means the syntax is correct. “Valid” additionally means the document matches a schema (XSD/DTD) defining allowed elements. This tool checks well-formedness, which is the mandatory first step.
Why does the error point at the wrong line?
Parsers report where they detected the problem, which can be after the actual mistake — e.g. an unclosed tag is only noticed at the next sibling or end of file. Scan backwards from the reported position.
Does it validate against an XSD schema?
No — schema validation needs the schema file and a dedicated validator. This tool confirms the XML is well-formed, which every downstream tool requires.
Is my XML uploaded anywhere?
No. Validation runs entirely in your browser — your data never leaves your device.
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