XML Validator: Validate & Verify XML Format Online
To validate XML format means checking that a document is well-formed: every tag closed, properly nested, one root element, attributes quoted, and special characters escaped. Paste your XML and you get back either a green confirmation with document statistics, or the exact parser error with a plain explanation of how to fix it.
How it works
- 1
Paste the XML you want to verify into the editor.
- 2
Click Validate XML: the document is parsed with the browser's strict XML parser.
- 3
Read the verdict: valid (with element/namespace/size statistics) or the precise error and the common fix for that error class.
Frequently asked questions
How do I check if my XML format is valid?
Paste it above and click Validate. The tool runs a strict well-formedness parse: if anything is wrong you get the parser's exact message (and line where available) plus a plain-English explanation of the usual cause; if it's clean you get a statistics report.
What's the difference between well-formed and valid XML?
Well-formed means the syntax is correct (closed tags, proper nesting, quoted attributes). Valid goes further: the document also conforms to a schema (XSD/DTD) that defines which elements are allowed where. This tool checks well-formedness; schema validation requires the XSD file.
What are the most common XML validation errors?
In practice: unescaped & characters in text or URLs (use &), mismatched or unclosed tags, attribute values without quotes, multiple root elements, and an XML declaration that isn't on line 1 column 1. Each produces a distinctive parser message the validator explains.
Can I validate XML from a URL?
For WSDL URLs, use the WSDL Analyzer which fetches and validates server-side. For arbitrary XML URLs, fetch the content and paste it here; browsers block cross-origin fetches of raw XML, so a paste is the reliable route.
Is my XML stored when I validate it?
No. Validation runs entirely in your browser via DOMParser. Nothing is transmitted or stored.
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