XML Formatter - Prettify & Validate Free

Format and prettify XML with proper indentation and syntax validation. Customizable indent size. Free online XML beautifier.

XML Formatter - Prettify & Validate XML Online

Format, prettify, and validate XML documents with proper indentation and line breaks. Transform minified or messy XML into a readable, well-structured format. The formatter validates your XML structure and highlights errors, making debugging straightforward.

The formatter parses your XML using a DOM parser, validates the document structure for well-formedness, and reconstructs it with consistent indentation. It handles processing instructions, CDATA sections, comments, namespaces, and self-closing tags correctly. Invalid XML triggers clear error messages pointing to the problem location.

Backend developers debug SOAP API responses and requests. DevOps engineers read XML configuration files for web servers (Apache, IIS) and application servers. Data engineers process RSS/Atom feeds and data interchange files. Frontend developers format SVG files for readability and editing.

When working with large XML files, format small sections at a time to isolate structural errors. Pay attention to namespace declarations - missing or incorrect namespaces are a common source of parsing errors. Always validate your XML against its schema (XSD) if one is available, not just for well-formedness.

While IDEs like VS Code and IntelliJ have built-in XML formatting, this browser-based tool is faster for quick one-off formatting tasks without opening a project. For JSON formatting and data format conversions, check out the related tools below.

How the XML Formatter Works

  1. 01Paste your minified or messy XML into the input field
  2. 02The formatter parses the XML and validates its structure
  3. 03View the beautified output with proper indentation and line breaks
  4. 04Copy the formatted XML or download as a file

Working with XML Documents

XML is still widely used in SOAP APIs, RSS feeds, SVG files, and enterprise integrations. Properly indented XML is much easier to debug and review. Common issues include unclosed tags, mismatched nesting, and unescaped special characters (&, <, >). This formatter catches structural errors and shows exactly where the problem is in your markup.

When to Use the XML Formatter

Use this formatter whenever you encounter minified or poorly indented XML that is difficult to read. This commonly happens with SOAP API responses, auto-generated XML configuration files, SVG files exported from design tools, and XML database dumps. Proper formatting makes debugging and code review significantly faster.

Common Use Cases

Expert Tips

  • Use 2-space indentation for XML that will be stored in version control - it reduces diff noise compared to 4-space or tab indentation
  • If formatting fails, the error message points to the first parsing error - fix that issue first as subsequent errors are often cascading
  • For XML with CDATA sections, the formatter preserves content inside CDATA blocks exactly as-is

Frequently Asked Questions

What is the difference between well-formed and valid XML?→
Well-formed XML follows basic syntax rules: properly nested tags, matching open/close tags, and quoted attribute values. Valid XML additionally conforms to a specific schema (XSD or DTD) that defines allowed elements and structure. This formatter checks for well-formedness but not schema validation.
Does the formatter change my XML content?→
No, the formatter only changes whitespace and indentation. Your element content, attributes, CDATA sections, and comments remain unchanged. The output is semantically identical to the input - only the visual layout changes.
Can I format SVG files with this tool?→
Yes, SVG is valid XML and can be formatted with this tool. This is useful when editing SVG files by hand or debugging SVG rendering issues. Formatted SVG makes it easy to find and modify specific elements, paths, and styling.

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