XML Validator

Check whether XML is well-formed and pinpoint errors.

ToolsSoup's XML Validator is a free online tool that instantly checks whether your XML is well-formed and, when it is not, pinpoints the line and column of the first error with a clear message. Everything runs in your browser — no uploads, no sign-up, and your data never leaves your device.

What is an XML validator?

An XML validator parses your document and checks that it follows the rules of well-formed XML: every tag is closed, opening and closing tags match and nest correctly, attribute values are quoted, and special characters are escaped. If the XML is valid, you get a confirmation with a quick summary; if not, the validator reports the exact line and column of the first problem so you can fix it fast.

How to validate XML online

Validating XML with ToolsSoup takes just a few seconds:

  1. Paste or type your XML into the input box.
  2. Click Validate to check it against the rules of well-formed XML.
  3. Read the result: a green confirmation, or a red message with the line and column of the first error.

Well-formed vs valid XML

This tool checks that your XML is well-formed — syntactically correct. That is different from validating against a schema (DTD or XSD), which also checks that the elements and attributes match a defined structure. Well-formedness is the first requirement for any XML, and it is what most 'invalid XML' errors come down to.

Why use this XML validator?

  • 100% free with no ads, sign-up, or usage limits.
  • Runs entirely in your browser — your data is never uploaded to a server.
  • Pinpoints the line and column of the first error.
  • Confirms valid XML and summarizes the root element.
  • Works with SOAP, RSS, SVG, and any XML document.

Frequently asked questions

Is this XML validator free?

Yes. Every tool on ToolsSoup is completely free to use, with no account, sign-up, or hidden limits.

Is my XML data safe?

Absolutely. All validation happens locally in your browser using JavaScript, so your XML is never sent to or stored on any server.

What does well-formed mean?

Well-formed XML follows the basic syntax rules: a single root element, properly closed and nested tags, quoted attribute values, and escaped special characters. The validator checks exactly this.

Does it validate against a DTD or XSD schema?

No. This tool checks well-formedness, not schema validity. Validating against a DTD or XSD also verifies that your elements and attributes match a defined structure, which is a separate step.

Why does it say my XML is invalid?

The most common causes are unclosed tags, mismatched opening and closing tags, more than one root element, unquoted attribute values, and unescaped & or < characters. The line and column in the error point you to the first issue.