XML Formatter
Format, beautify, and validate XML documents with proper indentation.
Why I Built This XML Formatter
I still work with XML more than I'd like to admit - legacy APIs, SOAP services, enterprise integrations, config files. Everyone says JSON won, but XML keeps showing up in my projects. This formatter makes it bearable. Paste your messy XML, click Format, and get properly indented output with validation errors highlighted.
What This Tool Does
- Auto-formatting - I hate squinting at single-line XML. This adds proper indentation and line breaks
- Validation - Catches malformed XML before it breaks your parser
- Minification - When you need to strip whitespace for production
- Statistics - Quick element and attribute counts for large documents
- Comment Handling - Keep or strip comments based on your needs
XML Rules I Keep Forgetting
After years of working with XML, I still occasionally forget these rules. Maybe you do too:
- All elements must have closing tags or be self-closing (no <br> like HTML)
- Elements must be properly nested - no overlapping tags
- Attribute values must be quoted (single or double)
- Tag names are case-sensitive - <Item> and <item> are different
- There must be exactly one root element wrapping everything
The full spec is the W3C XML Recommendation — worth bookmarking if you work with XML regularly.
I often use this with the YAML ↔ JSON Converter when migrating configs between formats, and the Diff Checker when comparing XML versions from different environments.
Related Articles
- XML in 2026: When I Still Reach for It Over JSON
- JSON vs YAML vs XML: Which One Should You Actually Use?
Frequently Asked Questions
What's the difference between XML and HTML?
XML is way stricter. In HTML, you can get away with unclosed tags and unquoted attributes - browsers are forgiving. XML parsers are not. Every tag must close, every attribute must be quoted, and case matters. I learned this the hard way when an uppercase tag broke a SOAP integration.
Why is my XML showing as invalid?
In my experience, it's usually one of these: unclosed tags somewhere, mismatched tag names (remember, case matters!), unquoted attribute values, missing root element, or special characters that need escaping (&, <, >). The error message should point you to the line number.
Is my XML data stored anywhere?
No way. I built all my tools with privacy in mind - everything runs in your browser using the native DOMParser API. Your XML never leaves your device. I don't want to see your enterprise configs any more than you want me to.