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XML Formatter & Validator

Format, beautify, minify, and validate XML in your browser.

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Format and validate XML online — instantly, in your browser

Unformatted or minified XML is nearly impossible to read or debug. This free XML formatter takes any valid (or broken) XML and immediately produces clean, consistently indented output with proper nesting. It also validates the document and highlights the exact line and character position of any syntax error, so you can fix problems without guessing.

XML formatting vs minification — when to use each

Formatted XML uses indentation (typically 2 or 4 spaces) to visually represent the document hierarchy. Use this when reading, reviewing, or debugging XML in a code editor, version control diff, or documentation. Minified XML strips all whitespace between tags to reduce file size. Use minification for production deployments, API payloads, embedded configurations, and any situation where bandwidth or storage matters.

Common XML validation errors and what they mean

The most frequent XML errors are unclosed tags (every opening tag needs a matching closing tag), mismatched tag names (case-sensitive — <Item> and <item> are different), illegal characters in attribute values (use &amp; for &, &lt; for <), multiple root elements (XML allows only one root node), and malformed declarations (the XML declaration must be the very first line). This validator pinpoints which line and column triggered the error, so you can jump straight to the problem.

Use cases for XML formatting

XML is still widely used in enterprise software despite JSON's rise. Common scenarios where this formatter helps: debugging SOAP API requests and responses, reading Android manifest or layout files, inspecting Maven or Gradle POM files, validating RSS and Atom feed output, cleaning up exported configuration files from tools like Jenkins or SonarQube, and reviewing SVG source code for graphics work.

Your data stays private

XML often contains sensitive information — database exports, API credentials in config files, customer data in SOAP payloads. This tool runs entirely in your browser; your XML is never sent to a server, never logged, and is gone when you close the tab.

Frequently asked questions

What types of XML can I format?
Any well-formed XML can be formatted, including RSS and Atom feeds, SOAP messages, SVG files, Maven POM files, Android resource files (strings.xml, layout.xml), Spring configuration files, and generic data XML used in integrations and APIs.
How is XML validation done?
The tool uses the browser's built-in DOMParser with the 'application/xml' MIME type. If the XML is malformed — for example, unclosed tags, invalid attribute syntax, or illegal characters — the parser returns a parsererror element that includes the exact error message and line number where the problem was detected.
Does formatting preserve XML attributes?
Yes. All attributes, namespace declarations, processing instructions, CDATA sections, and XML comments are preserved exactly as written. Only indentation and whitespace between elements is changed. The formatter does not reorder or modify attribute values in any way.
Is my XML sent to a server?
No. All formatting, validation, and minification is performed using the browser's built-in XML parser and serializer. Your XML data never leaves your device. This makes it safe to format XML containing API credentials, internal configurations, or sensitive business data.

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