XML Formatter — Free Online XML Beautifier & Validator

Writing clean XML matters. Whether you are editing a Sitemap, parsing an API response, configuring a Maven build file, or debugging SOAP messages, unformatted XML is impossible to read. Our free online XML Formatter instantly beautifies and validates raw XML — with proper indentation, tag hierarchy, and nesting — entirely in your browser.

What is XML and Why Does Formatting Matter?

XML (eXtensible Markup Language) is a self-describing, hierarchical text format used across thousands of systems: Android layouts, RSS/Atom feeds, web service payloads (SOAP, REST), database exports, office documents (DOCX, XLSX), SVG graphics, and configuration files.

Unlike HTML, XML is case-sensitive and strictly structured. A single unmatched tag or a missing closing element breaks the entire document. Formatting XML properly:

• Reveals structure: Indented hierarchy makes it immediately clear which elements are parents and which are children
• Exposes errors: Mismatched tags stand out visually in formatted XML
• Enables collaboration: Team members can quickly review well-formatted XML in code review
• Simplifies debugging: Log files and API dumps often contain flattened single-line XML that is unreadable without formatting

How to Use the XML Formatter

1. Paste your XML into the input area — raw, minified, or partially formatted
2. Click Format XML
3. Review the indented, structured output
4. Click Copy to grab the formatted XML

The formatter uses your browser’s built-in DOMParser to parse the document, ensuring valid XML is properly structured. If your XML contains an error, the tool reports the exact error message so you can fix it.

Example

Before (minified input):

<?xml version="1.0"?><catalog><book id="bk101"><author>Gambardella, Matthew</author><title>XML Developer Guide</title><price>44.95</price></book></catalog>

After (formatted output):

<?xml version="1.0"?>
<catalog>
  <book id="bk101">
    <author>Gambardella, Matthew</author>
    <title>XML Developer Guide</title>
    <price>44.95</price>
  </book>
</catalog>

Common XML Use Cases

Frequently Asked Questions

Does the formatter validate my XML?

Yes. The formatter uses the browser’s native DOMParser with application/xml MIME type. If your XML contains any syntax error (unclosed tag, mismatched quotes, etc.), the formatter will display the parser’s error message rather than attempting to format invalid input.

What indentation size does it use?

The output uses 2-space indentation, which is the most widely used standard for XML in modern codebases and matches the default setting in VS Code and most XML editors.

Can I format XML with namespaces or DTD declarations?

Yes. Namespace prefixes (xmlns:xsi, xsi:type) and DTD declarations are preserved in the output. The formatter focuses on readability without stripping any document-level declarations.

Is my XML data private?

Completely. All parsing and formatting runs inside your browser tab using native DOM APIs. Your XML is never sent to any server. This makes it safe to format sensitive configuration files, credentials, or private API responses.

What’s the difference between XML and JSON formatting?

Both are hierarchical data formats, but XML uses angle-bracket tags while JSON uses curly braces. XML supports attributes, comments, and namespaces that JSON does not. If you need to convert between the two, use our XML to JSON Converter or JSON to XML Converter.

How do I minify XML instead of formatting it?

If you need to compress XML for production use (removing all whitespace and newlines), use our JSON Minifier approach: after formatting, minify by removing all indentation. For XML specifically, the formatted output from this tool is the best starting point before any minification pipeline.