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XML Formatter

Format, validate, and minify XML data using browser-native parsing

Input XML

Paste your XML here

Formatted XML

Formatted or minified XML

Formatted XML will appear here

About XML Formatter

Format, validate, and minify XML data using browser-native parsing. Perfect for developers working with APIs, configuration files, or any XML data. All processing happens in your browser - no data is sent to any server.

Why Use This Tool?

  • ✓ Format minified or compressed XML instantly for readability - API responses, config files (web.xml, pom.xml), and SOAP messages often arrive as unreadable one-liners, this tool adds proper indentation and line breaks making structure obvious
  • ✓ Validate XML syntax before deployment to catch errors early - finds unclosed tags, mismatched opening/closing tags, invalid characters, improper nesting that would crash parsers or break applications, preventing production errors
  • ✓ Minify XML for production to reduce file size by 20-40% - removes whitespace, newlines, unnecessary spacing for faster API responses, smaller config files, reduced bandwidth costs especially important for high-traffic SOAP/XML-RPC services
  • ✓ Debug SOAP/REST XML APIs by inspecting formatted request/response payloads - understand complex nested structures, verify data being sent/received, troubleshoot integration issues with third-party XML APIs without writing parsing code
  • ✓ 100% client-side processing means sensitive data never leaves browser - safely format XML containing API keys, customer data, health records, financial information without sending to external formatters that might log inputs

Features

  • Format XML with proper indentation
  • Minify XML to reduce file size
  • Validate XML syntax using browser parser
  • 100% client-side processing for privacy

Common Questions

  • Q: What's the difference between XML and JSON? Both are data interchange formats but different philosophies: XML = verbose, extensible, supports attributes/namespaces/schemas, better for document-oriented data (SVG, Office docs, SOAP). JSON = lightweight, simpler syntax, no attributes/schemas, better for object-oriented data (REST APIs, config files, JavaScript). File size: JSON typically 20-30% smaller. Parsing: JSON faster and easier. Use XML when: working with legacy systems, need complex validation (XSD schemas), document markup (HTML-like), SOAP APIs. Use JSON for: modern REST APIs, JavaScript apps, simpler data structures. Industry trend: JSON replacing XML except where XML is entrenched (banking, healthcare, government).
  • Q: How do I validate XML against a schema (XSD)? XML validation has two levels: (1) Well-formed = basic syntax rules (matching tags, proper nesting, valid characters) - this tool validates this level using browser parser. (2) Valid = conforms to schema (XSD/DTD) defining allowed elements, attributes, data types, structure rules. This tool does basic well-formedness only. For schema validation: use dedicated XSD validators, programming language XML libraries (lxml in Python, javax.xml in Java), or online XSD validators. XSD validation ensures data structure matches expected format (e.g., 'age' must be integer 0-120, 'email' must match pattern).
  • Q: Why does my XML work in one parser but fail in another? XML parsers vary in strictness. Common issues: (1) Encoding declaration - some parsers require header, others don't. (2) Namespace handling - lenient parsers ignore undeclared namespaces, strict parsers error. (3) Character entities - & < > must be used instead of & < >, some parsers auto-escape. (4) Whitespace - some preserve all whitespace, others trim. (5) DOCTYPE and entities - some parsers reject external DTDs for security. Test XML in target parser, not just browser validator. Use strict parsers during development to catch issues early.
  • Q: Should I use attributes or child elements in XML? Design choice with tradeoffs. Attributes: compact (), good for metadata/IDs, can't contain complex data or lists. Elements: verbose (123John), support nested structures, easier to extend. Guidelines: use attributes for: IDs, simple metadata, enums, data that won't need nesting. Use elements for: data that might grow complex, lists/arrays, anything that needs child elements later. When in doubt, use elements - more flexible. Example: Book... - ISBN is attribute (simple ID), authors are elements (list).
  • Q: How do I handle special characters and CDATA in XML? XML reserves characters: < > & " ' must be escaped. Escape as: < > & " ' (or numeric < >). Example: 5 < 10 (correct), 5 < 10 (invalid). CDATA sections for large blocks of special characters: & without escaping]]>. Use CDATA for: code snippets, HTML content, anything with lots of < > &. Don't use CDATA for: small text (escaping is fine), data that needs XML parsing. CDATA can't be nested. Most XML libraries handle escaping automatically when creating XML, only worry about it when manually writing XML strings.

Pro Tips & Best Practices

  • 💡 Format XML before debugging SOAP API issues: SOAP responses are notoriously complex and minified. Copy response from network inspector, paste into formatter, instantly see structure with proper indentation. This makes debugging SOAP faults, finding nested error messages, and understanding response structure trivial instead of painful. Bookmark this tool for SOAP API development - you'll use it constantly. Also useful for SOAP request construction - format your request XML to verify structure before sending.
  • 💡 Validate XML config files before deployment to catch typos: XML config files (web.xml, pom.xml, applicationContext.xml, Android layouts) with syntax errors cause cryptic startup failures. Before committing/deploying, paste config into validator - catches unclosed tags, typos in element names, mismatched quotes that IDE might miss. Takes 5 seconds, prevents 30-minute debugging sessions. Especially important for configs you edit manually (not generated) - humans make typos.
  • 💡 Minify XML for production only, keep formatted for development: Don't manually minify XML files you need to edit (config files, test data) - wastes time and makes future edits error-prone. Keep files formatted for readability in version control. Use build tools to minify automatically: Maven/Gradle plugins for Java configs, build scripts for other XML. Only manually minify when: embedding XML in code as string, pasting into systems without build pipeline, creating compact one-time payloads.
  • 💡 Use XML namespaces correctly to avoid element name conflicts: Namespaces prevent naming collisions when combining XML from multiple sources. Format: data. Default namespace (no prefix): xmlns="http://namespace-uri" applies to all descendants. Common mistake: forgetting namespace prefix in XPath queries - use namespace-aware XPath. When validating XML with namespaces, ensure namespaces are declared, otherwise 'element not defined' errors. Most XML APIs handle namespaces automatically.
  • 💡 Understand XML vs HTML parsing differences: HTML parsers are forgiving (auto-close unclosed tags, ignore mismatched tags, allow attributes without quotes). XML parsers are strict (any syntax error fails parsing). Don't use XML tools on HTML - it will fail. Don't assume HTML rules apply to XML - XML requires: closing all tags, matching case exactly ( ≠ ), quoting all attributes, no shortcuts like
    must be

    or self-closing
    . Use HTML parsers for HTML, XML parsers for XML. XHTML is XML-strict HTML (all HTML must follow XML rules).

When to Use This Tool

  • SOAP API Development: Format SOAP request/response XML to understand complex nested structures, debug SOAP faults and error messages with readable formatting, validate SOAP envelopes before sending to verify correct structure
  • Configuration File Management: Format and validate Java config files (web.xml, pom.xml, beans.xml), verify Android layout XML and manifest files for syntax errors, debug Spring/Maven configuration issues by inspecting formatted XML
  • Data Exchange & Integration: Format XML from legacy systems or EDI transactions for analysis, validate XML data files before importing into databases or systems, debug XML-based integrations (RSS, Atom, sitemap.xml, KML)
  • Document Processing: Inspect and format Office XML (docx, xlsx are ZIP files containing XML), format SVG files (scalable vector graphics in XML format), debug XSLT transformations by formatting input/output XML
  • API Response Debugging: Format XML responses from REST APIs that still use XML, inspect RSS/Atom feed XML for parsing issues, debug XML-RPC responses and payloads
  • Schema & Validation: Prepare XML for XSD schema validation by formatting for readability, verify XML structure matches expected schema before validation, format XML examples for documentation or API specifications

Related Tools

  • Try our JSON Formatter for formatting JSON data (most modern APIs use JSON instead of XML)
  • Use our Base64 Encoder/Decoder to encode XML for transmission in systems that don't handle special characters
  • Check our Regex Tester to test patterns for extracting data from XML using regular expressions
  • Explore our CSV Formatter to format and validate CSV data as an alternative to XML for tabular data

Quick Tips & Navigation