XML Formatter
Format, pretty-print, or minify XML code instantly in your browser.
XML Formatter Features
Fast, private XML formatting directly in your browser.
Switch between pretty-print and minify modes to expand or compress your XML.
Detects XML errors immediately and shows a clear error message.
Your XML stays on your device. Privacy-aware, no sign-up needed.
Key Takeaways
- The formatter runs entirely in your browser using the built-in DOMParser, so your XML is processed on your device.
- Use Format mode to pretty-print XML with 2-space, 4-space, or Tab indentation for reading and debugging, and Minify mode to strip whitespace into one compact string for API payloads and storage.
- Because the tool parses before output, invalid XML (such as an unclosed tag or extra root element) is reported with the first parse error instead of being formatted, giving you a quick validity check.
- Processing is limited by your browser's memory, so files up to a few megabytes format almost instantly while very large documents may run slow and are best split first.
How to Format or Minify XML
Paste XML into the input area
Drop your XML into the left input box. The tool reads it with the browser's built-in DOMParser, so everything stays on your device and nothing is uploaded. A single unformatted line works fine - the parser handles the structure for you.
Pick an indent and a mode
Set Indent to 2 spaces, 4 spaces, or Tab, then choose Mode. Format expands the XML with line breaks and nesting; Minify collapses it to one compact string. The indent setting only applies in Format mode.
Click Format XML, then Copy
Press Format XML to render the result on the right. If the input parses cleanly you get a success message; use Copy to send the output to your clipboard, or Clear to reset both panels and start over.
Format Mode vs Minify Mode
Both modes first parse your XML with DOMParser and re-serialize it, so the data stays identical. The difference is only in the whitespace they produce and where each output is best used.
| Aspect | Format (pretty-print) | Minify |
|---|---|---|
| Line breaks | One element per line | Removed |
| Indentation | 2 spaces, 4 spaces, or Tab | None |
| Output size | Larger, more readable | Smallest possible |
| Best for | Debugging, code review, editing by hand | API payloads, storage, data transfer |
| Whitespace between tags | Added to show hierarchy | Stripped between tags |
| Data and structure | Unchanged | Unchanged |
Which Setting Should You Use?
Reading and debugging
Use Format mode with 4 spaces. The wide indentation makes deep nesting easy to scan and is the most common convention for XML config and data files.
Matching a code base
Choose Tab if your project indents with tabs, so the formatted output drops straight into source control without reformatting diffs. Pick 2 spaces for more compact, screen-friendly nesting.
Shipping to an API
Switch to Minify mode. It removes line breaks and collapses runs of whitespace into single spaces, producing a compact string that is lighter to send and store.
Checking validity quickly
Paste and click Format. Because the tool parses with DOMParser before output, an invalid document is reported with the first parse error instead of being formatted, giving you a fast sanity check.
Common Problems and Fixes
It says "Invalid XML" and shows no output
The DOMParser found a syntax problem - usually an unclosed or mismatched tag, an unquoted attribute, a stray ampersand, or more than one root element. Fix the spot named in the error message and click Format XML again.
Indentation looks slightly off on mixed content
The formatter indents based on opening and closing tags. Elements that mix text and child tags on the same line can produce uneven spacing. Splitting that content into separate child elements gives cleaner nesting.
My indent choice did nothing
The indent size only affects Format mode. In Minify mode all whitespace is stripped, so 2 spaces, 4 spaces, and Tab all produce the same compact line. Switch back to Format to see indentation.
A very large file feels slow or stalls
Processing runs in your browser, so it is bound by available memory. Files up to a few megabytes format almost instantly; for much larger documents, close other tabs or split the file before formatting.
What is XML and When Should You Format It?
XML (Extensible Markup Language) is a widely-used format for structured data, configuration files, and APIs. Formatting XML improves readability and makes debugging much easier. Our free online XML formatter lets you instantly beautify messy XML or minify it for production use - all without leaving your browser.
Frequently Asked Questions
What is XML formatting?
XML formatting (also called pretty-printing or beautifying) reorganizes XML code with consistent indentation and line breaks so it is easy for humans to read.
Unformatted XML is often a single long line with no whitespace, which is difficult to read and debug.
Formatted XML preserves the same data but adds indentation and newlines to show the hierarchy clearly.
What is XML minification?
XML minification removes all unnecessary whitespace, newlines, and indentation to produce the most compact possible XML string.
Minified XML is ideal for APIs and data transfer where file size matters and human readability is not required.
Our tool supports both formatting and minification in one click.
Does the formatter validate my XML?
Yes. The formatter uses the browser's built-in XML parser. If your XML is invalid it will show the exact parse error.
Common errors include unclosed tags, mismatched tags, and illegal characters.
Fix the error in the input and click Format again.
What indentation options are available?
You can choose 2 spaces, 4 spaces, or a tab character for indentation.
4 spaces is the most common convention for XML files.
Tabs are preferred in some code bases where tab width is configurable.
Is XML different from HTML?
XML and HTML look similar but serve different purposes. HTML is for presenting web content; XML is for storing and transporting structured data.
XML is stricter - all tags must be closed, attribute values must be quoted, and the document must have a single root element.
For formatting HTML use our dedicated HTML Formatter tool.
Can I format very large XML files?
Yes, within browser memory limits. Files up to several megabytes are processed instantly.
For very large files (100MB+) a server-side tool may be more appropriate.
Most XML files encountered in practice are well within browser limits.
Does formatting change the data?
No. Formatting only adds or removes whitespace. The actual data, element names, and attribute values are never changed.
The formatted XML is semantically identical to the original.
You can verify this by parsing both versions - they produce the same DOM tree.
Is my data private?
Yes. All XML processing happens entirely in your browser using JavaScript. No data is sent to any server.
This makes the tool safe to use with sensitive configuration files or proprietary data.
We do not log, store, or transmit any content you paste into the tool.
Sources and References
Format and tool details on this page are based on the official specifications and documentation below.
- Extensible Markup Language (XML) 1.0- W3C
- XML introduction- MDN Web Docs