XML Formatter & Validator

About This Tool

The XML Formatter & Validator is a free online tool that instantly transforms messy or minified XML into clean, readable code with proper indentation. It validates your XML against the W3C specification, catching syntax errors such as unclosed tags, mismatched elements, and malformed attributes before they cause runtime failures in your application.

All processing runs entirely in your browser using the native DOMParser API — no data is ever sent to a server. You can safely format sensitive configuration files, internal API responses, or proprietary XML payloads without any privacy concerns.

How to Use

1. Paste your XML content into the Input panel on the left.
2. Choose your preferred indentation (2 or 4 spaces) from the dropdown.
3. Click Fmt to format and validate, or Min to minify.
4. Review the result in the Output panel. Syntax errors appear highlighted below.
5. Click Copy to copy the formatted output to your clipboard.

Use Cases

Developers use this tool to format XML API responses, Maven pom.xml files, Android AndroidManifest.xml, SOAP envelopes, SVG source, and Spring/Hibernate configuration files. QA engineers use it to debug XML payloads from test suites. Data engineers validate data feeds before pipeline ingestion. The minify feature reduces payload size for production XML APIs and embedded configuration.

FAQ

• What XML versions are supported? — XML 1.0 and 1.1, including all standard entities, CDATA sections, processing instructions, and namespace declarations.
• Does it preserve namespaces? — Yes. All namespace prefixes and declarations (xmlns:) are preserved exactly as provided.
• Is my data safe? — All parsing and formatting happens locally in your browser. No XML data is ever transmitted to any server.
• What does Minify do? — Minify removes all whitespace between tags, producing the most compact valid XML. Useful for reducing network payload size.