How to use the XML formatter
- Paste XML into the left box.
- Pick indent (2 spaces default, 4 spaces, tab, or minified single line).
- Formatting runs automatically after 300ms of idle typing. Ctrl/⌘+Enter to run manually.
- Any parse error shows in the status bar with the browser's message.
Why XML still matters in 2026
JSON won most new APIs, but XML powers: SOAP (enterprise integrations), SAML (SSO), RSS/Atom (podcasts, news), MusicXML, OPF/EPUB (ebooks), OOXML/ODF (Word, Excel, LibreOffice), SVG (every icon on the web), Android manifest files, and every serious config system in the Java/.NET world. Knowing XML well still pays.
What this tool validates (and what it doesn't)
This tool validates well-formedness — that the XML parses: tags are balanced, quotes are
matched, entities are well-formed, the document has a root element. It does not validate
against a DTD, XSD, or RELAX NG schema — that requires loading the schema and running a validator
(xmllint, Saxon, or a runtime library).
Common XML errors
- Unbalanced tags — every
<tag>needs</tag>or must self-close. - Unescaped ampersand —
&in content or attributes must be&. - Attributes without quotes — XML requires quotes around every attribute value.
- Multiple root elements — XML docs must have exactly one top-level element.
- XML declaration in wrong place —
<?xml ... ?>must be the very first thing, no whitespace before.
FAQ
Does the formatter preserve namespaces?
Yes — namespace prefixes and xmlns:* attributes pass through untouched.
What about CDATA sections?
CDATA is preserved verbatim. The formatter does not reflow or escape its contents.
Is this private?
Yes. The browser's built-in DOMParser does all the work locally. No data leaves your machine.
Related tools
- JSON Formatter — Format, validate, and beautify JSON online. 100% client-side — your data never leaves your browser.
- YAML ↔ JSON Converter — Convert between YAML and JSON formats with full fidelity.
- CSV to JSON Converter — Convert CSV files to JSON with proper quoting and escaping.
- JSON Diff — Compare two JSON objects structurally with field-by-field diff.
Pillar
Part of Data & Format — JSON, YAML, XML, CSV, SQL, Markdown.
Written by Mian Ali Khalid. Last updated 2026-04-25.