Free Online XML Formatter & Validator
Beautify, minify, and validate XML online. Pretty-print with 2 or 4-space indentation, strip whitespace for minification, and check well-formedness. Free, 100% client-side.
100% Client-Side · Your data never leaves your browserHow to Use XML Formatter & Validator
Paste your XML into the Input panel on the left, then pick a mode from the toolbar:
- Beautify — validates and pretty-prints the XML with your chosen indentation (2 or 4 spaces). The output appears in the right panel with readable line breaks and consistent nesting.
- Minify — strips all whitespace between tags to produce the most compact valid XML string, ideal for production payloads.
- Validate — checks your XML for well-formedness errors without modifying it. A green banner means the XML is valid; a red banner shows the exact parse error.
Press Ctrl/Cmd+Enter to run the active operation, or click the mode button. Use the Copy button above the output panel to copy the result. Press Ctrl/Cmd+K to clear both panels.
Frequently Asked Questions
What does "Beautify XML" do?
Beautify (also called pretty-print) parses your XML and re-outputs it with consistent indentation and line breaks, making it easy for humans to read. The content — tags, attributes, and text nodes — stays identical; only the whitespace changes.
What does "Minify XML" do?
Minification removes all unnecessary whitespace between tags, producing the most compact valid XML string. This is useful when you want to reduce payload size before sending XML over a network or storing it.
How do I validate my XML?
Switch to the "Validate" mode and click the button. The tool uses the browser's built-in DOMParser to check for well-formedness errors (mismatched tags, illegal characters, missing closing tags, etc.) and reports the exact error message if found.
Does this tool support XML namespaces and processing instructions?
Yes. The formatter preserves namespace declarations (xmlns), namespace-prefixed elements, and processing instructions (<?xml version="1.0"?>, <?php ... ?>, etc.) without modifying them.
Is my XML data sent to a server?
No. All XML processing runs entirely in your browser — validation uses the native DOMParser API, and formatting uses a client-side algorithm. Your data never leaves your machine.
Why is the formatter not handling my HTML file correctly?
HTML is not strict XML (it allows unclosed tags, attribute values without quotes, etc.). If you need to format HTML, use an HTML-specific tool. For XHTML — which is strict XML — this formatter works perfectly.