XML / HTML Formatter
Format, validate, and minify XML or HTML securely in your browser. Your data never leaves your device, ensuring sensitive configuration files remain private.
Output appears hereFormat, validate, and minify XML and HTML instantly with SolveBar's XML/HTML Formatter. Get clean indentation, syntax error highlighting with line numbers, and production-ready minified output — all running in your browser with your data staying private.
XML vs HTML formatting rules
XML is strict: all tags must be closed, attribute values must be quoted, the document must have a single root element, and case matters. HTML5 is more forgiving: some tags are self-closing, attribute quotes are optional in some cases, and browsers apply error correction.
When to minify XML or HTML
Minification removes whitespace and comments to reduce file size. For HTML, minification can reduce page size by 10-30%, improving load times. XML configuration files in production deployments are often minified to reduce bandwidth.
Common XML validation errors
The most common XML errors are unclosed tags, mismatched tag names (case-sensitive), invalid characters in tag names (must start with a letter or underscore), and ampersands or angle brackets in text content that need escaping (& < >).
Frequently Asked Questions
Can this formatter handle very large XML files?
Yes, though very large files (10MB+) may take a few seconds to process in the browser. For production processing of large files, consider command-line tools like xmllint.
Does it support XML namespaces?
Yes. XML namespaces (xmlns attributes and prefixed element names) are preserved correctly during formatting.
Can I format SVG files?
Yes. SVG is valid XML and formats correctly. The minified output is useful for inlining SVGs in HTML or CSS.