</> XML Formatter & Validator
Format, beautify, minify and validate XML. Runs entirely in your browser.
Last updated: May 18, 2026 · By Λ
Free XML Formatter, Beautifier & Validator
Instantly format, beautify, minify and validate XML data. Choose between 2-space, 4-space, or tab indentation. View your XML with syntax highlighting or as a collapsible tree structure. Validates well-formedness and shows detailed error messages with line and column info. Parsing and pretty-printing happen inside the page you are viewing, so the XML you paste is never uploaded anywhere. Perfect for developers, API debugging, and configuration file editing. No account required, completely free.
What is XML?
XML (Extensible Markup Language) is a flexible, structured data format used to store and transport information. Unlike HTML, which has predefined tags, XML allows you to define your own tags, making it a powerful choice for representing complex, hierarchical data. XML is widely used in web services (SOAP APIs), configuration files (Maven pom.xml, Android layouts, .NET config files), data interchange between enterprise systems, and document formats like SVG, RSS feeds, and Microsoft Office files.
Working with XML often means dealing with minified or poorly formatted documents that are difficult to read. API responses may arrive as a single long line, or configuration files may lose their indentation after automated processing. This formatter lets you instantly beautify XML with proper indentation, minify it for compact storage or transmission, and validate its structure to catch errors before they cause problems in your application. The tool includes syntax highlighting and a collapsible tree view for visual exploration of document structure.
How to Use This Tool
- Paste your XML content into the input panel on the left side. You can also load a sample XML document using the sample button to try the tool before using your own data.
- Choose your preferred indentation style (2 spaces, 4 spaces, or tabs) from the dropdown at the top.
- Click "Beautify" to format the XML with proper indentation and line breaks, "Minify" to compress it into a single line, or "Validate" to check for structural errors without changing the content.
- View the output in the right panel with syntax highlighting, or switch to the tree view for an interactive, collapsible representation of the document structure. Use "Copy" to copy the formatted result.
Key Features
- Beautify and Minify - Format XML with configurable indentation for readability, or compress it to a single line for efficient storage and transmission.
- Validation - Check XML well-formedness and get detailed error messages with line and column numbers to quickly locate problems in your document.
- Syntax Highlighting - Color-coded output distinguishes tags, attribute names, attribute values, text content, comments, CDATA sections, and processing instructions.
- Tree View - An interactive collapsible tree representation of your XML document, allowing you to expand and collapse nodes to explore the structure visually.
- Flexible Indentation - Choose between 2-space, 4-space, or tab indentation to match your project's coding standards.
Frequently Asked Questions
What does "well-formed XML" mean?
Well-formed XML follows the basic syntax rules of the XML specification: every opening tag has a matching closing tag (or is self-closing), tags are properly nested without overlapping, attribute values are quoted, and the document has exactly one root element. The validator in this tool checks all of these rules and reports any violations with their exact location in the document.
What is the difference between XML validation and XML schema validation?
This tool checks for well-formedness, which means it verifies that the XML follows correct syntax rules. Schema validation (using XSD, DTD, or RelaxNG) goes further by checking that the content conforms to a specific structure, such as requiring certain elements to appear in a particular order or restricting attribute values to specific types. This tool focuses on well-formedness checks, which is the most common need when debugging XML issues.
Why would I minify XML?
Minifying XML removes all unnecessary whitespace, including indentation and line breaks, reducing the file size. This is useful when transmitting XML over networks where bandwidth matters, storing XML in databases where space is a concern, or embedding XML in other formats. Minified XML contains the same data and structure as the formatted version, just without the visual formatting.
Can I format XML with namespaces and CDATA sections?
Yes. The formatter correctly handles XML namespaces (including prefixed elements and default namespace declarations), CDATA sections, comments, processing instructions, and entity references. The syntax highlighter uses distinct colors for each of these elements, making it easy to distinguish between different parts of complex XML documents.