XML Validator

Paste or drop any XML document and instantly check if it's well-formed. Invalid XML shows the exact error location and context. Valid XML displays element count, depth, attribute stats, and namespace info. Nothing leaves your browser.

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XML Input
📄 Drop an .xml file here, or

What This Tool Does

Validates XML document syntax in your browser, checking for well-formedness errors including unclosed tags, mismatched nesting, and illegal characters — with exact line and column numbers.

Who This Is For

  • Backend developers debugging XML payloads from third-party APIs or SOAP services
  • Data engineers validating XML exports before importing into downstream systems
  • Anyone hand-editing XML configuration files who wants to catch errors before deployment
  • Developers writing XML generation code who want to verify output structure

Example: Input: An XML document that may have unclosed tags, mismatched nesting, or encoding issues → Output: A pass/fail result with the exact line number and error description for every well-formedness violation found

Error Details
Document Info

How It Works

1
Paste or drop your XMLPaste XML into the editor, or drag-and-drop an .xml file. Supports any XML format — SOAP, RSS, SVG, config files, etc.
2
Click ValidateThe validator parses the XML using the browser's built-in DOMParser and checks for well-formedness errors.
3
Review resultsErrors show the exact line and column. Valid XML shows document stats — element count, depth, attributes, and namespaces.

Common XML Errors This Tool Detects

ErrorExampleFix
Unclosed tag<name>AliceAdd closing </name>
Mismatched tags<Name>...</name>XML is case-sensitive — match exactly
Unescaped ampersandAT&TUse &amp; for &
Unquoted attribute<book id=1>Quote it: id="1"
Spaces in tag names<First Name>Use underscores: <First_Name>
No root elementTwo sibling top-level tagsWrap in a single root element
Invalid charactersControl characters (0x00–0x1F)Remove or encode them

When to Use This Tool

  • Debugging SOAP API responses that fail to parse
  • Checking XML configuration files (.config, .csproj, web.xml) for syntax errors
  • Validating RSS or Atom feed XML before publishing
  • Verifying SVG files are well-formed before embedding in HTML
  • Checking XML output from a JSON to XML conversion

🔒 Privacy & Security

All validation runs in your browser using the built-in DOMParser API. No XML is uploaded to any server. This is important when validating XML that contains SOAP credentials, configuration secrets, API tokens, or customer data.

You Might Also Need

XML to JSON → JSON to XML → HTML Formatter → JSON Validator →

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Frequently Asked Questions

What does an XML validator check?
An XML validator checks whether the document is well-formed: all tags are properly opened and closed, attributes are quoted, element names follow XML naming rules, and there is exactly one root element.
What is the difference between well-formed and valid XML?
Well-formed XML follows the basic XML syntax rules. Valid XML also conforms to a schema (DTD, XSD, or RelaxNG). This tool checks for well-formedness — the most common source of XML errors.
Why does my XML fail with "not well-formed"?
Common causes include unclosed tags, mismatched tag names (XML is case-sensitive), unescaped ampersands or angle brackets in text content, missing quotes around attribute values, and element names containing spaces.
Can I validate XML from an API response?
Yes. Copy the raw XML from your API response and paste it into the validator. It will immediately check the syntax and report any errors with line numbers.
Does this tool validate against XSD schemas?
No. This tool validates XML well-formedness only. Schema validation (XSD/DTD) requires a schema file and is better handled by tools like xmllint or IDE plugins.
Is my XML data kept private?
Yes. All validation runs in your browser using the built-in DOMParser API. No XML data is sent to any server.