XML Formatter

Format, minify, and validate XML — copy and paste the result.

This free online XML formatter pretty-prints or minifies XML, with adjustable indentation. Comments, CDATA sections, and the XML declaration are preserved exactly. Invalid XML shows a clear parser error instead of a broken result. No signup required, runs entirely in your browser.

Examples:

Mode

Indent

Preserved as-is

<?xml version="1.0"?>
XML declaration
<!-- comment -->
Comments
<![CDATA[ ... ]]>
CDATA sections
XML Input
Valid XML

What does an XML formatter do?

An XML formatter takes XML text and re-outputs it with consistent, readable indentation — turning a dense, single-line SOAP response or config file into something you can actually scan. This tool validates the input first using your browser's native XML parser, so if your document isn't well-formed, you get a clear error instead of a broken or empty result.

Format vs minify

Format (pretty-print) adds indentation and line breaks so nested elements are easy to read — pick 2 spaces, 4 spaces, or a tab. Minify does the opposite: it strips every insignificant whitespace-only text node between tags, producing the smallest possible valid XML — useful when you're about to send the payload over the network and don't need it to be human-readable.

What gets preserved

Comments (<!-- ... -->), CDATA sections (<![CDATA[ ... ]]>), and the XML declaration (<?xml version="1.0" encoding="UTF-8"?>) are all kept exactly as written in both modes. Only whitespace between tags — the parts that don't affect the document's meaning — is added or removed.

Common XML syntax errors

  • Mismatched tags — <a><b></a></b> is invalid; every opening tag must close in the reverse order it opened.
  • Unclosed elements — every <tag> needs a matching </tag> or a self-closing <tag/>.
  • Multiple root elements — a well-formed XML document can only have one top-level element; everything else must be nested inside it.
  • Unescaped special characters — a raw & or < inside text content must be written as &amp; or &lt;.

This tool uses your browser's native XML parser, so error messages match exactly what your browser's engine reports.

Working with other structured data?

See the JSON Formatter for JSON, or the Hex to Decimal Converter and UUID Generator for other developer utilities.

Frequently asked questions

Paste your XML into the input above with the mode set to Format. The tool validates it and pretty-prints it with your chosen indentation (2 spaces, 4 spaces, or a tab). Invalid XML shows a clear parser error instead of a broken result.
Switch the mode to Minify. The tool removes all insignificant whitespace between tags and outputs the XML as compactly as possible — useful for reducing payload size before sending it over the network.
Yes. Every format or minify pass first parses the XML with your browser's built-in XML parser. If the document isn't well-formed — a mismatched tag, an unclosed element, invalid characters — the parser's error message is shown instead of a result.
Yes. Comments, CDATA sections, and the XML declaration (<?xml version="1.0"?>) are all kept exactly as written — only whitespace between tags is added or removed depending on the mode.
No. Everything is parsed and formatted locally in your browser using the native XML parser. Nothing is uploaded or stored on a server.
DesignRevision
' }, { label: 'Invalid (mismatched tags)', value: '' }, ], get _result() { const text = this.input; if (!text.trim()) return { ok: true, value: '' }; try { if (this.mode === 'minify') { return { ok: true, value: minifyXml(text) }; } const space = this.indent === 'tab' ? '\t' : ' '.repeat(Number(this.indent)); return { ok: true, value: formatXml(text, space) }; } catch (e) { return { ok: false, value: '', error: e.message }; } }, get output() { return this._result.value; }, get parseError() { return this._result.ok ? null : this._result.error; }, loadExample(ex) { this.input = ex.value; }, clearInput() { this.input = ''; }, async copyOutput() { const text = this.output; if (!text) return; try { await navigator.clipboard.writeText(text); } catch { const el = document.createElement('textarea'); el.value = text; document.body.appendChild(el); el.select(); document.execCommand('copy'); document.body.removeChild(el); } this.copied = true; setTimeout(() => { this.copied = false; }, 2000); }, })); if (window.Alpine) { register(); } else { document.addEventListener('alpine:init', register); } })();