XML Formatter & Validator Online Free
Paste any XML and instantly beautify it with proper indentation, or minify it to a compact single line. Validates well-formedness on every run. No upload, no signup.
XML Formatter & Validator
How to Format XML
- 1Paste your XML into the input box — it can be minified, partially indented, or already formatted.
- 2Choose an indent size (2 or 4 spaces) from the dropdown, then click Beautify to pretty-print or Minify to compress.
- 3If the XML is invalid, an error message appears describing the problem. Fix the XML and try again.
- 4Click Copy to copy the result to your clipboard.
What Is XML?
XML (eXtensible Markup Language) is a text format for encoding structured data. Unlike JSON, XML uses opening and closing tags — similar to HTML — and supports attributes, namespaces, and mixed content (text and child elements inside the same element). It is the foundation of formats like SVG, DOCX, XLSX, RSS, Atom, SOAP web services, and Android layout files.
Well-formed XML must follow strict rules: every opening tag must have a matching closing tag, tags must be properly nested, attribute values must be quoted, and special characters like & and < must be escaped as entities. This tool validates all of these rules when you click Beautify or Minify.
Tips for Working with XML
Escape Special Characters
Use & for &, < for <, > for >, " for ", and ' for '. Unescaped characters are the most common cause of parse errors.
Use CDATA for Raw Text
Wrap blocks of text that contain special characters in <![CDATA[...]]> to avoid escaping every character. Anything inside CDATA is treated as literal text by XML parsers.
XML Is Case-Sensitive
<Item> and <item> are different tags. Mismatched case between opening and closing tags is one of the most common XML errors and is easy to miss visually.
Validate Before Converting
When using our XML-to-JSON converter, format and validate the XML here first. A well-formed XML file converts cleanly; a malformed one produces unpredictable results in converters.
Frequently Asked Questions
What does the XML Formatter do?
The formatter parses your XML using the browser's built-in DOMParser and re-serialises it with consistent indentation and line breaks. Each element gets its own line, and child elements are indented relative to their parent. The structure and content of the XML are unchanged — only whitespace is adjusted to make it easier to read.
How does XML validation work?
When you click Beautify or Minify, the tool attempts to parse the input as well-formed XML. If the XML is malformed — for example, a missing closing tag, mismatched tag names, or an illegal character — the parser reports an error and the error message is displayed instead of formatted output. Fixing the reported error will allow the XML to be formatted.
What is the difference between Beautify and Minify?
Beautify (pretty-print) adds indentation and line breaks so the XML is easy to read. Each element is on its own line, and children are indented by 2 or 4 spaces. Minify removes all non-essential whitespace to produce the smallest possible representation of the same XML — useful for storage or transmission where byte count matters.
Is my XML sent to a server?
No. Parsing, validation, and formatting all run in JavaScript inside your browser using the built-in DOMParser and XMLSerializer APIs. Your XML is never transmitted over the network and is never stored anywhere outside your device.
What XML features are supported?
The tool supports standard well-formed XML including elements, attributes, text content, CDATA sections, and comments. It handles the XML declaration (<?xml version="1.0"?>) and preserves it in beautified output. Namespaces are supported. DTD validation is not performed — the tool checks well-formedness only, not schema conformance.
Why does my XML show a parser error even though it looks correct?
Common causes include: an unescaped & that should be &, a < inside a text node that should be <, mismatched tag names (XML is case-sensitive, so <Item> and <item> are different), a missing closing tag, or an attribute value not wrapped in quotes. The error message from the browser parser usually identifies the line and character where the problem was detected.