How to Format & Validate
XML Online Free
Prettify minified XML, catch syntax errors with line numbers, minify back for transport. Browser-only.
Open XML FormatterWhy a dedicated XML formatter?
XML is harder to read than JSON when minified — closing tags add to the visual noise, and namespace prefixes make every element name twice as long. A 300-character SOAP envelope on one line is unreadable. Properly indented, it's a 30-second skim.
And unlike JSON, XML errors are often subtle — an unescaped ampersand inside an attribute, a closing tag with the wrong case, a CDATA block missing its closing bracket. A formatter that runs DOMParser tells you about these immediately, with line numbers, before you waste time debugging the consumer.
Step-by-step: format XML in seconds
Open the XML Formatter
Visit the free XML Formatter. The tool runs entirely in your browser using DOMParser and XMLSerializer — the same primitives the browser uses to parse XHTML.
Paste raw XML into the input
Drop in any XML — SOAP envelopes, RSS/Atom feeds, SVG markup, sitemap files, OOXML fragments. The parser is namespace-aware and handles CDATA sections correctly.
Pick indentation
2-space, 4-space, or tab. 2 spaces is the most common convention; tabs are useful when the output will be opened in tab-based editors. The choice doesn't affect parser behaviour, just readability.
Read errors with line numbers
If the XML is malformed, the parser reports the exact line and column. Common issues: unclosed tags, mismatched element names, ampersands not escaped as &, or invalid characters in attribute values.
Copy or download the formatted output
Click Copy to grab the prettified XML, or Download to save as .xml. The Minify button does the reverse — collapses to one line for transport.
Pro tips
Validate before formatting
Formatting won't fix errors — it just rearranges whitespace. If your XML has a missing close tag, the formatter rejects it and shows you where. Fix the structural error first, then format.
Mind XML namespaces in copy/paste
If you paste a fragment from inside an SVG or SOAP envelope without the parent's namespace declaration, the formatter may complain about an undeclared prefix. Either copy the parent element with its xmlns:... attribute, or add the declaration manually.
CDATA stays intact
Anything inside <![CDATA[...]]> is preserved character-for-character — script content, raw HTML, embedded queries. The formatter doesn't try to indent or escape inside CDATA blocks.
Don't format gigabyte-scale XML
DOM parsing loads the entire tree into memory. For very large XML files (50+ MB), use a streaming SAX parser at the command line instead. The formatter is designed for everyday config-file-sized payloads.
SOAP requests with API tokens stay on your device
XML often carries credentials — SOAP security headers, OAuth flows, internal API responses with PII. Format any of it without worrying about it leaving your browser tab.
Frequently asked questions
What's the difference between formatting and validating?
Formatting changes whitespace (indentation, line breaks) without altering the data. Validating checks that the XML is well-formed — properly nested, balanced tags, escaped entities, valid attribute syntax. The formatter does both: validation is a prerequisite for formatting, so you get error reports for free.
Can it validate against an XSD or DTD?
Not currently. The browser's DOMParser checks well-formedness only — it doesn't enforce schema validation. For XSD/DTD validation use a desktop tool like xmllint or oXygen. The formatter is for the much more common case of 'is this XML even parseable'.
Does it handle SOAP, RSS, Atom, SVG?
Yes — all four. They're all just XML with conventions for what tags mean. The formatter doesn't care about semantics; it'll prettify any well-formed XML. SOAP envelopes with nested namespaces, Atom entries with HTML in CDATA, and SVG with embedded scripts all format cleanly.
Why does my XML say 'Extra content at the end'?
XML requires exactly one root element. If your input has two top-level elements (e.g. two <product>s with no enclosing parent), parsers reject it. Wrap in a <root>...</root> or <items>...</items> to give it a single root.
Will my XML be uploaded?
No. Parsing and formatting happen entirely in your browser via DOMParser and XMLSerializer. SOAP requests with API tokens, RSS feeds with email addresses, anything else — none of it is transmitted.
Can I format JSX or HTML?
JSX no — JSX isn't valid XML (unquoted attributes, JS expressions). HTML... usually no — most HTML is not well-formed XML (unclosed <br>, <img> without /, etc.). For HTML, use a Prettier-style HTML formatter. For XHTML it works.