XML Formatter & Beautifier

XML arrives in two unreadable forms: one endless line from a machine, or a wall of inconsistent indentation from several machines arguing. This formatter fixes both, parsing your XML with the browser’s real XML parser — so validation is genuine, not cosmetic — then re-emitting it with clean, configurable indentation. It reports structural errors with the parser’s own message instead of producing pretty nonsense, and it can also minify formatted XML back down for transmission. Feeds, configuration files, SOAP payloads, sitemaps and SVG-adjacent markup all become something a human can finally read, diff and debug.

Quick Answer: Paste XML to pretty-print it with clean indentation and genuine validation, or minify it — errors are reported, not hidden.

Free Online Tool

One-line XML in, readable XML out — genuinely parsed.

XML input
<catalog><book id="b1"><title>Structure and Interpretation</title><author>Abelson</author></book><book id="b2"><title>Design Patterns</title><author>Gamma</author></book></catalog>
Indent

How to Use the XML Formatter & Beautifier

Paste your XML, however mangled or minified.
Choose your indent (2 spaces, 4 spaces or tab).
Press Format to beautify, or Minify to compress.
If the XML is malformed, read the parser’s error message to find the fault.
Copy the result for your editor, config or payload.

Key Features

Real parsing via the browser’s XML engine — true validation.
Configurable indentation: 2 spaces, 4 spaces or tabs.
Minify mode strips insignificant whitespace for compact payloads.
Attributes preserved exactly; nothing is reordered or ‘helpfully’ rewritten.
Your configs and payloads never leave the browser.

Best Practices and Tips

A well-formedness error stops everything downstream — fix the reported fault first; XML parsers are strict because the format demands it.
Diff two payloads after formatting both: structure differences leap out once indentation matches.
Minify only copies for transmission; keep the formatted version as your readable source of truth.
Sitemaps and feeds benefit most — one-line sitemap XML becomes auditable in seconds.
Remember XML is case-sensitive and every tag must close (or self-close): the validator enforces the same rules your server will.

Common Mistakes to Avoid

Expecting the formatter to fix broken XML — beautifying requires parsing, and parsing requires valid structure.
Confusing well-formed with valid: this checks well-formedness (structure); schema/DTD validation against a specific vocabulary is a server-side job.
Minifying XML that carries significant whitespace (like some document formats) and changing its meaning.
Pasting HTML and expecting XML rules — HTML’s optional closing tags make it malformed XML until tidied.

Frequently Asked Questions

How does the validation work?

The pasted markup is parsed with DOMParser, the browser’s standards-compliant XML parser. Malformed input produces a parsererror document, whose message this tool surfaces verbatim — the same diagnosis your server-side parser would give you.

Will formatting change my data?

No. Formatting adjusts only the whitespace between elements. Element names, attributes, text content and order are preserved exactly; the serialiser re-emits the parsed structure faithfully.

What is minified XML for?

Smaller payloads for transmission and storage — configuration shipped to devices, feeds polled frequently, embedded data. The information content is identical; only readability is traded away, which is why minification here is one click and reversible.

Can it format very large XML?

Documents of a few megabytes parse and format comfortably. Extremely large files belong in desktop editors with streaming parsers; the browser will tell you honestly via a slow tab rather than a wrong answer.

Does it handle namespaces and declarations?

Yes — XML declarations, comments, CDATA sections and namespace prefixes all survive the round trip, because a real parser carries them rather than a regex pretending to.