XML Formatter & Validator

Free Online XML Formatter, Beautifier & Validator

Instantly format, beautify, minify, and validate any XML document right in your browser. No data leaves your machine — everything is processed 100% client-side.

What Can This Tool Do?

Beautify XML — Pretty-print with customizable indentation (2 spaces, 4 spaces, or tabs)
Minify XML — Remove all unnecessary whitespace for compact output
Validate XML — Check for well-formedness errors with descriptive messages
Tree View — Visualize XML structure as an interactive tree
Sort Attributes — Alphabetically sort element attributes for consistency
Stats — See element count, attribute count, nesting depth, and file size

Common XML Formats Supported

RSS/Atom Feeds — Format blog and podcast feeds
SVG Files — Clean up vector graphic markup
Sitemaps — Validate and beautify sitemap.xml files
SOAP — Format web service request/response envelopes
Maven POM — Clean up Java project files
Android Layouts — Format Android XML resources
XHTML — Format strict HTML documents

XML vs JSON

XML uses tags and attributes for structured data, while JSON uses key-value pairs. XML supports schemas, namespaces, comments, and processing instructions — making it better for configuration files, document markup, and enterprise integrations. JSON is lighter and more common in modern REST APIs.

Well-Formed XML Rules

Must have exactly one root element
All opening tags must have matching closing tags (or be self-closing)
Tags are case-sensitive: <Item> ≠ <item>
Attribute values must be quoted
Elements must be properly nested (no overlapping)
Special characters (&, <, >) must be escaped

Frequently Asked Questions

What is XML and how is it different from JSON?

XML (eXtensible Markup Language) uses tags to structure data, like HTML but for arbitrary data. JSON uses key-value pairs with curly braces. XML supports attributes, namespaces, comments, and mixed content (text with child elements). JSON is more compact and widely preferred for modern APIs. XML remains dominant in enterprise systems, SOAP services, RSS feeds, and configuration files.

What does an XML formatter actually do?

An XML formatter parses raw XML and outputs it with consistent indentation, line breaks, and whitespace. Minified XML compresses everything to one line for performance. Pretty-printed XML adds two or four spaces per nesting level for readability. Formatters also validate that the XML is well-formed — catching unclosed tags, mismatched elements, or invalid characters.

What is the difference between well-formed and valid XML?

Well-formed XML follows basic XML syntax rules: one root element, properly nested tags, quoted attributes, and closed tags. Valid XML additionally conforms to a specific schema like DTD or XSD, which defines allowed elements, attributes, and their data types. All valid XML is well-formed, but well-formed XML isn't necessarily valid against a specific schema.

What are XML namespaces and why are they used?

XML namespaces prevent element name conflicts when combining XML from different sources. They're declared with xmlns: prefix and a URI. The URI is just a unique identifier, not necessarily a real URL. Namespaces are heavily used in SOAP, SVG, XHTML, and Office Open XML formats like .docx and .xlsx.

How do I convert XML to JSON?

Converting XML to JSON requires mapping XML constructs to JSON equivalents. Elements become object keys, text content becomes string values, attributes can be prefixed with @ or merged into the object. Arrays are created when sibling elements share the same name. Libraries like xml2js (Node.js), xmltodict (Python), or online converters handle this transformation automatically.

Related Free Tools

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Options

Samples

🌳 XML Tree View