XML Formatter
Format, validate, and minify XML. Beautify XML with customizable indentation or compress it to a single line.
Format XML with proper indentation for readability. Choose your preferred indent size.
Table of Contents
What is XML?
XML (eXtensible Markup Language) is a markup language that defines a set of rules for encoding documents in a format that is both human-readable and machine-readable. XML is widely used for representing structured data, configuration files, web services (SOAP), and data exchange between systems.
XML uses tags to structure data, similar to HTML, but allows you to define your own custom tags. It supports attributes, nested elements, and provides a flexible way to represent hierarchical data structures.
XML Formatting
Formatting XML makes it more readable by adding proper indentation and line breaks. This is especially useful when:
- Reviewing API responses and web service data
- Debugging configuration files
- Sharing XML data with team members
- Documenting data structures and schemas
- Learning XML structure and hierarchy
This tool allows you to choose your preferred indent size (2, 4, or 8 spaces, or tabs) to match your project's coding standards.
XML Minifying
Minifying XML removes all unnecessary whitespace, line breaks, and formatting to create the smallest possible file size. This is beneficial for:
- Reducing file size: Smaller files transfer faster over networks
- API responses: Minimize bandwidth usage in production
- Configuration files: Compact storage when readability isn't a priority
- Performance: Slightly faster parsing due to less data to process
- Web services: Reduce payload size for SOAP and REST API calls
Note: Minified XML is harder to read, so it's typically used in production environments where size matters more than readability.
XML Validation
This tool automatically validates your XML as you type. If the XML is invalid, you'll see an error message indicating what's wrong. Common XML errors include:
- Unclosed tags: Every opening tag must have a corresponding closing tag
- Mismatched tags: Opening and closing tag names must match exactly
- Improper nesting: Tags must be properly nested (cannot overlap)
- Unquoted attributes: All attribute values must be enclosed in quotes
- Special characters: Characters like <, >, & must be properly escaped or used within CDATA sections
- Invalid characters: Some characters are not allowed in XML
Common Use Cases
- API Development: Format XML responses for easier debugging
- Configuration Files: Format and validate config files like pom.xml, web.xml, or custom XML configs
- Web Services: Format SOAP requests and responses for testing
- Data Migration: Clean and format XML data before importing
- Code Reviews: Make XML diffs more readable in pull requests
- Documentation: Format XML examples in documentation
- Testing: Format test data and fixtures for better readability
- Production Optimization: Minify XML for smaller payload sizes
Best Practices
Use Consistent Indentation
Choose an indent size (typically 2 or 4 spaces) and use it consistently across your project. This makes XML files easier to read and maintain.
Validate Before Using
Always validate XML before using it in production. Invalid XML will cause parsing errors that can break your application or web service.
Format in Development, Minify in Production
Use formatted XML during development for readability, but minify it for production to reduce file size and improve performance.
Handle Errors Gracefully
When parsing XML in your code, always use try-catch blocks to handle potential parsing errors and provide meaningful error messages to users.
Escape Special Characters
Always properly escape special characters like <, >, and & in text content. Use CDATA sections for blocks of text that contain many special characters.
Use Meaningful Tag Names
Choose descriptive, meaningful tag and attribute names that clearly indicate their purpose. This makes XML more self-documenting and easier to maintain.
Frequently Asked Questions
Formatting adds indentation and line breaks to make XML readable, while minifying removes all whitespace to create the smallest possible file size. Use formatting for development and minifying for production.
Common causes include unclosed tags, mismatched tag names, improper nesting, unquoted attributes, or special characters that need escaping. Check the error message for specific details about what's wrong with your XML.
Yes! XML supports comments using <!-- --> syntax. Our formatter preserves comments and formats them appropriately. However, comments inside tag attributes are not supported.
2 or 4 spaces are the most common choices. Use 2 spaces for more compact formatting or 4 spaces for more visual separation. Choose based on your project's coding standards.
Minified XML is slightly faster to parse because there's less data to process, but the difference is usually negligible. The main benefit is reduced file size and bandwidth usage.
Yes. If your XML includes an XML declaration (like <?xml version="1.0" encoding="UTF-8"?>), it will be preserved in the formatted output.
No. Formatting only changes whitespace and structure, not the actual data or content. The parsed XML document remains identical whether it's formatted, minified, or somewhere in between.
This tool works best with XML that fits in memory. For very large files (hundreds of MBs), consider using command-line tools or specialized XML processors that can handle streaming or SAX parsing.
While HTML is similar to XML, HTML often uses features not valid in XML (like self-closing tags without slashes, unquoted attributes). This tool is designed for well-formed XML. For HTML, consider using an HTML-specific formatter that handles HTML's more lenient syntax.