XML Validator
Check that XML is well-formed and pinpoint the error.
Processed locally in your browser. Nothing you enter is uploaded or stored.
- Uses the same XML parser your browser relies on to render XML and feeds, so "valid here" means valid everywhere that matters.
- Surfaces the parser's own error message and location, not a generic failure.
- Runs in your browser; documents aren't uploaded.
Why this is private
- Processed locally in your browser. Nothing you enter is uploaded or stored.
- Open your browser's DevTools → Network tab while using this tool — you won't see a request carrying your input, because it never leaves your device.
- Nothing you enter is uploaded to a server or shared with us — the processing happens entirely on your device.
Overview
Checks whether XML is well-formed — properly nested and closed tags, one root element, valid attribute syntax — using your browser's own XML parser, and reports what's wrong.
How to use it
- 1Paste XML.
- 2Validation runs automatically as you type.
- 3If invalid, the parser's error message is shown.
Tips
- "Well-formed" isn't the same as "valid against a schema" — this checks that tags are properly nested and closed with one root element, not that your XML matches a specific DTD or XSD.
Frequently asked questions
What people use it for
Debug a rejected XML API requestPaste the payload your client is sending to find the exact malformed tag.
Check an RSS/Atom feed before publishingConfirm it's well-formed so feed readers don't choke on it.
Verify XML pasted from logs or a chatPasted XML often loses a closing tag — this points straight at the break.
Related guides
- How to read JSON with a tree viewerA tree viewer turns a wall of brackets into a structure you can expand, search and copy paths from. Here's how to use one effectively.
- JSON parse errors explained: 'Unexpected token', 'Expected comma or brace', and the restWhat each common JSON error message actually means, the usual cause, and how to find the spot fast using line and column.
- How to format JSON (and actually understand the errors)JSON looks like a JavaScript object but follows stricter rules. Here's what those rules are and how to read the errors when they're broken.
Related tools
All developer toolsReady to use XML Validator?
XML Validator