Processed locally — your file never leaves your device
XML Validator
Check whether XML is well-formed, with a clear error message if it isn't — entirely in your browser.
How it works
- Paste XML, or open a .xml file.
- Click Validate.
- See a confirmation if it's well-formed, or a specific error if it isn't — checked entirely on your device.
Frequently asked questions
- Is my XML uploaded anywhere?
- No. Validation happens locally using your browser's own built-in XML parser.
- What does 'well-formed' mean here?
- It checks XML syntax — matching tags, proper nesting, correctly quoted attributes, valid character use — not validation against a specific schema (like an XSD or DTD content model).
- Is it safe to check XML from an untrusted source?
- Yes. The browser's XML parser doesn't fetch external files or resolve external entities, so this tool can't be used to read files from your device or make network requests, even with a maliciously crafted file (an XXE attack).
- What do I get if the XML is invalid?
- A specific message describing the problem, generally including its approximate location.
- Can I open a file instead of pasting?
- Yes, there's an Open file button, or you can paste text directly.