XML Formatter & Validator

Paste your XML to format, validate, or minify it. Uses the browser's native XML parser - 100% client-side.

Last reviewed: April 2026
Reviewed by , software engineer · last updated April 2026

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Input XML
Output
Paste XML above to format or validate it.

Quick Answer

An XML formatter pretty-prints raw or minified XML with proper indentation and nesting, and validates that tags are well-formed. Paste your XML above to format and check it. Well-formed means every open tag has a matching close tag and elements are properly nested — this tool flags where that breaks. Everything runs locally in your browser.

How to Use the XML Formatter

To use the XML Formatter, simply paste your XML code into the input area on the left (or top on mobile). Choose a format mode - 2-space (default), 4-space, or Minify. Click the 'Format' or 'Minify' button to process your XML. The output will be displayed on the right side of the page.

When to Use the Tool in Real Workflows

The XML Formatter is ideal for developers working with XML data, such as Android application resources, Maven build systems, and enterprise data exchange formats. It's also useful for anyone who needs to validate and format XML data for web services, RSS feeds, and other XML-based applications.

How It Works

The XML Formatter uses your browser's native DOMParser API to parse and validate XML. The DOMParser is the same engine browsers use to process HTML and SVG documents, making it a reliable and standards-compliant validator. Unlike regex-based tools, it catches all well-formedness errors, such as unclosed tags, attribute quote violations, invalid characters in names, and missing root elements.

Tips, Edge Cases, or Limitations

For most debugging needs, well-formedness checking is sufficient. Schema validation against a specific XSD requires a server-side validator or a desktop application like Oxygen XML Editor. The XML Formatter is 100% client-side, so it doesn't send your data to a server. However, it's important to ensure that your XML data is well-formed and valid for your specific use case.

XML Debugging Checklist

For real XML work, validate the structure before you focus on indentation. Confirm there is exactly one root element, attributes are quoted, tags are nested in the right order, and text that contains markup characters is escaped. A formatter can make a document readable, but it cannot infer the intended structure from missing closing tags.

When troubleshooting feeds, Android resources, Maven files, SVG fragments, or SOAP payloads, paste a small failing sample first. Once the small sample validates, add surrounding nodes back in sections so the exact failure is easier to isolate.

Frequently Asked Questions

XML (eXtensible Markup Language) is a flexible text format for storing and transporting structured data. Unlike HTML, XML has no predefined tags - developers define their own element names.
No, your XML data is processed entirely on your browser. The XML Formatter does not send your data to a server.
A well-formed XML document follows the syntactic rules of the XML specification: exactly one root element, all opening tags closed, proper nesting, quoted attribute values, and no illegal characters.
JSON is generally preferred for modern REST APIs due to its compactness, readability, and broad library support. XML has advantages like namespaces, attributes, mixed content, schema validation, and XPath querying, but these are less commonly needed for typical API payloads.
The XML validator uses the browser's DOMParser API to detect any XML syntax errors. It checks for well-formedness and can provide error messages for easy debugging.