XML Formatter & Validator
Pretty-print, minify and validate XML — entirely in your browser. Your documents never leave the page.
- Runs in your browser
- No upload, no tracking
- Free forever
How it works
An XML formatter takes raw or minified XML and rewrites it with consistent indentation so the element hierarchy is readable and diff-friendly — while validating that the document is well-formed and preserving attributes, CDATA sections and comments. This tool runs entirely client-side, so even sensitive documents stay on your machine. It is built by JusDB, a managed database operations team, for inspecting configs, SOAP payloads and data-exchange files.
- 1
Paste your XML
Drop any XML document into the input panel — a full file with a declaration, or a single fragment.
- 2
Choose indentation
Pick 2 or 4 spaces of indentation for the pretty-printed output.
- 3
Format or minify
Format re-indents the document and surfaces any structural error with its line number; Minify collapses whitespace between tags into a compact document.
- 4
Copy or download
Copy the output to your clipboard or download it as a .xml file. Nothing is ever uploaded.
Frequently asked questions
- Does it validate XML?
- Yes. Before formatting, the input is validated and any structural error is reported with the line number so you can locate and fix it quickly.
- Are attributes, CDATA and comments preserved?
- Yes. The formatter keeps element attributes, CDATA sections and comments intact while re-indenting the document for readability.
- Is my XML sent to a server?
- No. Parsing, validation and formatting all run in your browser using fast-xml-parser. Your XML never leaves your machine.
- What indentation can I choose?
- You can format with either 2 or 4 spaces of indentation. Minify removes indentation entirely and collapses whitespace between tags.
- What is the difference between formatting and minifying XML?
- Formatting (pretty-printing) adds indentation and line breaks so nested elements are easy to read and diff. Minifying strips whitespace between tags to produce the most compact valid document, useful for transport or storage.
- Can I download the formatted XML?
- Yes. After formatting or minifying, you can copy the output to your clipboard or download it as a .xml file straight from the output panel.
Working with XML in 2026: where it still matters and how to keep it clean
XML is far from dead. It quietly underpins enterprise SOAP services, Maven and Spring configuration in the Java world, .csproj and app.config files across .NET, RSS feeds and XML sitemaps, SVG vector graphics, and the OOXML formats behind every .docx and .xlsx. If you touch any of those, you eventually need to read, diff or repair an XML document — and a well-formatted file is the difference between spotting a bug in seconds and squinting at a single 4,000-character line.
Pretty-print to read, minify to ship
Pretty-printing adds indentation and line breaks so the element tree mirrors the document's logical structure. That makes code review and version-control diffs sane: a one-attribute change shows up as a one-line change rather than a churned blob. Minifying does the opposite, stripping inter-tag whitespace to shrink payloads for transport, caching or embedding in another file. A useful rule of thumb is to keep XML pretty-printed in your repository and minify only at the boundary where it leaves your system.
One caveat: whitespace between elements is not always insignificant. In mixed content (text interleaved with child elements, common in documents and SVG), and wherever >xml:space="preserve"< is set, reformatting can alter meaning. Treat config and data-exchange files as safe to reindent, but be careful with prose-bearing markup.
The pitfalls that actually bite
Most "broken XML" traces back to a handful of recurring mistakes. Unescaped special characters are the classic offender: a raw & in a URL, or a stray < inside text, makes the parser choke. Use the entities &, < and >, or wrap literal blocks in a CDATA section so the parser leaves them untouched. Encoding is the next trap — declare the right charset in the XML declaration, and watch for a UTF-8 byte-order mark (BOM) sneaking in ahead of the declaration, which some strict parsers reject.
Namespaces trip up almost everyone: a default xmlns and a prefixed one are not interchangeable, and copy-pasting a fragment out of its namespaced parent can silently change which schema it binds to. Finally, decide deliberately between attributes and child elements — attributes suit single scalar metadata, elements suit repeatable or structured data — because retrofitting that choice later is painful.
Well-formed is not the same as valid
This formatter checks that your document is well-formed: tags are balanced, properly nested and correctly escaped. Validity is a stronger, separate guarantee — it means the document also conforms to a schema (XSD, DTD or RELAX NG) that pins down which elements may appear, in what order, and with which data types. A file can be perfectly well-formed yet completely invalid against the contract a downstream service expects, so when an integration fails despite clean-looking XML, reach for schema validation next.
Everything here runs client-side: parsing, validation and formatting happen in your browser via fast-xml-parser, so credentials in a SOAP envelope or secrets in a config file never leave your machine. Working with other formats too? Try our JSON formatter for APIs that have moved on from XML, and read more on data tooling on the JusDB blog.