XML Formatter & Validator
Format, validate, and minify XML instantly in your browser
No data is sent to any server — everything runs client-side
XML Input
Paste your XML here
Result
Formatted or minified output
What Is XML Formatting?
XML formatting (pretty-printing) adds consistent indentation and line breaks to an XML document to make its hierarchical structure visually clear. Minified XML removes all non-essential whitespace to reduce file size for storage and transmission. Both operations preserve the document's data content and structure — only whitespace between tags changes.
Well-formatted XML is essential when reviewing configuration files (web.xml, pom.xml, .csproj), debugging SOAP responses, inspecting RSS/Atom feeds, or sharing XML structures with team members. Minified XML is used in production SOAP payloads, embedded XML in databases, and anywhere bandwidth or storage costs matter.
XML Validation: Common Errors
The validator checks whether your input is well-formed XML. Here are the most common errors developers encounter:
Mismatched tags
Every opening tag must have a matching closing tag with the same name. <item>...</items> is invalid.
Unescaped special characters
Characters like &, <, and > must be escaped as &, <, > in text content and attribute values.
Missing root element
XML documents must have exactly one root element wrapping all content. Multiple top-level elements are not allowed.
Unquoted attribute values
Attribute values must be enclosed in either single or double quotes: <item id="42"> not <item id=42>.
Invalid element names
Element names cannot start with numbers or contain spaces. Names are case-sensitive, so <Item> and <item> are different elements.
When to Use This Tool
Debugging SOAP Responses
SOAP API responses are often returned as a single line of XML. Formatting makes it easy to see the Envelope, Header, Body structure and locate the data payload within nested elements.
Reviewing Config Files
Validate and format XML config files like web.xml, pom.xml, .csproj, or AndroidManifest.xml before committing. Catch mismatched tags and escaping issues early.
Inspecting RSS & Atom Feeds
RSS and Atom feeds are XML documents. Format them to see channel metadata, item structure, and enclosure details clearly before parsing in your application.
Minifying for Production
Remove whitespace from XML payloads before embedding in databases, sending over APIs, or including in SOAP requests to reduce bandwidth and storage costs.
XML Structure Quick Reference
| Component | Example | Notes |
|---|---|---|
| Element | <name>value</name> | The basic building block of XML |
| Attribute | <item id="42"> | Key-value metadata on an element |
| Self-closing | <br/> | Element with no content |
| CDATA | <![CDATA[raw text]]> | Unescaped text block |
| Comment | <!-- note --> | Ignored by parsers |
| Declaration | <?xml version="1.0"?> | Optional, specifies version & encoding |
| Namespace | xmlns:ns="http://..." | Avoids name collisions between schemas |
Related Tools & Guides
Frequently Asked Questions
What is the difference between well-formed and valid XML?▼
Well-formed XML follows XML syntax rules: every tag is closed, attributes are quoted, and there is a single root element. Valid XML additionally conforms to a schema (DTD or XSD) that defines what elements and attributes are allowed. This tool checks well-formedness only.
Does formatting change the meaning of my XML?▼
No. Formatting only adds or removes whitespace between tags. The document's data content, element hierarchy, attribute values, and processing instructions remain identical.
Why does minified XML sometimes look different after formatting?▼
The xml2js library round-trips XML through a JavaScript object and back. Self-closing tags may be expanded, attribute order may change, and the XML declaration may be added or modified. The data structure is preserved, but cosmetic representation may differ.
What is a CDATA section and when should I use it?▼
CDATA sections (<![CDATA[...]]>) allow you to include text that contains characters like < and & without escaping them. They are useful for embedding JavaScript, HTML, or SQL inside XML without escaping every special character.
Can I format XML with namespaces?▼
Yes. XML namespaces (xmlns:prefix="uri" attributes) are handled by the parser and preserved in the output. Namespace declarations appear on the elements where they were originally declared.
Further Reading
Built by JDApplications