XML Formatter & Validator

Format, validate, prettify, and minify XML data objects and markup files.

XML Input

Output Result

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The Structure of XML and Best Practices for Formatting Tags

Extensible Markup Language (XML) is a text-based markup language used to structure, store, and transport data. While JSON has become more common for web APIs, XML remains widely used in legacy systems, configuration files, and sitemaps.

Rules of Well-Formed XML Documents

Unlike HTML, XML has strict markup rules:

  • Every opening tag must have a corresponding closing tag.
  • Tags must be nested correctly without overlapping.
  • XML tags are case-sensitive.
  • Attribute values must be enclosed in quotes.

Contextual Developer Utilities

If you are converting data payloads between XML and JSON configurations, check our JSON Formatter. If you are generating XML sitemaps for Google Search Console, use our dedicated Sitemap Generator.

Frequently Asked Questions

What makes XML "well-formed"?
An XML document is well-formed if it adheres to all XML syntax rules (balanced tags, single root element, quotes around attributes).
How does minifying XML improve performance?
Minifying removes unnecessary whitespace, tabs, and line breaks, reducing file transfer size and load times over network connections.