What is XML?
An XML validator checks whether your XML is well-formed — every tag is properly closed and nested, attributes are quoted, and there is a single root element. It reports the first error so you can fix it. Well-formed XML is required by every XML parser, so this catches the mistakes that break SOAP, RSS, config and SVG files. This tool checks XML instantly and privately in your browser.
Runs locally: your XML is checked in your browser; nothing is uploaded.
How XML works
The validator parses the XML and reports problems:
- It reads the document according to XML well-formedness rules.
- If everything is properly nested, closed and quoted, the XML is well-formed.
- If not, it reports what and where the error is.
How to use
- Paste your XML into the input box.
- The tool processes it instantly in your browser.
- Copy the result.
Examples
| Input | Result |
|---|---|
<note><to>Sam</to></note> | Well-formed |
<note><to>Sam</note> | Invalid — tag not closed correctly |
<a href=test>x</a> | Invalid — attribute value must be quoted |
Options explained
- Auto Update — Checks as you type.
Common uses
- Validating SOAP and API XML before sending.
- Checking RSS feeds and config files.
- Finding unclosed tags and quoting errors.
Frequently asked questions
What does 'well-formed' mean?
Tags are properly nested and closed, attributes are quoted, and there is exactly one root element.
Is well-formed the same as valid against a schema?
No. Well-formedness checks syntax; validating against a DTD or XSD additionally checks structure rules.
How do I format XML?
Use the XML Formatter to indent it.