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XML Validator

Validate XML syntax online. Check if your XML is well-formed and find errors.

How to Use XML Validator

1

Paste your XML document

Copy your XML content from any source and paste it into the validator editor. The tool accepts XML of any size.

2

Review validation results

The validator instantly checks for well-formedness and displays any errors with line numbers, column positions, and descriptive messages.

3

Fix reported errors

Click on each error to jump to the problematic location. Follow the error description to fix issues like unclosed tags, improper nesting, or unquoted attributes.

4

Re-validate until clean

After making fixes, the validator re-checks automatically. Continue until no errors remain and your XML is confirmed well-formed.

About XML Validator

XML validator online — check your XML documents for syntax errors and well-formedness instantly. This free XML validation tool identifies unclosed tags, improper nesting, invalid characters, malformed attributes, and namespace issues with precise line and column numbers. Essential for developers debugging SOAP services, RSS feeds, SVG files, and configuration XML. Runs entirely in your browser for complete data privacy.

Key Features

  • Validate XML well-formedness with detailed error reporting
  • Pinpoint exact line and column numbers for every syntax error
  • Check proper tag nesting, closing tags, and attribute quoting
  • Instant validation as you paste or type XML content
  • Validate XML namespaces and character encoding declarations
  • Color-coded error highlighting directly in the editor

Frequently Asked Questions

How to validate XML online for free?▾
Paste your XML into the editor and the validator instantly checks for well-formedness errors. Any issues are highlighted with exact line numbers and descriptive error messages. No signup required.
How to check if XML is well-formed?▾
Well-formed XML has properly opened and closed tags, correct nesting, quoted attribute values, and a single root element. The validator checks all these rules and reports violations.
How to find errors in XML documents?▾
The validator highlights errors directly in the editor with red markers. Click on an error to jump to the exact line and column where the issue occurs.
How to validate XML namespaces?▾
The validator checks that namespace prefixes are properly declared and used consistently throughout the document. Undeclared prefixes are flagged as errors.
How to validate XML encoding declarations?▾
The validator checks that XML declarations (<?xml version="1.0" encoding="UTF-8"?>) are properly formatted and placed at the document start.
How to fix common XML syntax errors?▾
Common errors include unclosed tags (add the closing tag), unquoted attributes (wrap values in quotes), and improper nesting (ensure tags close in reverse order). The error messages guide you to each fix.
How to validate large XML files in the browser?▾
The validator efficiently parses large XML documents. For files over 10MB, validation may take a few seconds depending on your device performance.