XML formatter
XML formatter is a developer tool that formats, minifies, and validates XML documents. It uses the browser's native DOMParser and XMLSerializer, handles SOAP envelopes, RSS feeds, SVG, and config files, and surfaces parser errors with location detail. The tool runs in your browser.
Input XML
Formatted XML
ACTION
Runs entirely in your browser
Dedicated pages
Direct links for specific XML workflows.
Format XML Online
Format XML documents with consistent indentation. Works with SOAP, RSS, SVG, and config files. All processing runs in your browser using DOMParser.
XML Pretty Printer
Pretty-print XML in your browser with readable indentation. Supports namespaces, CDATA, and comments. Free, runs entirely client-side.
Minify XML
Strip whitespace from XML documents to reduce payload size for transport or storage. All processing runs in your browser using DOMParser.
How to format XML
- Paste the XML document into the input pane.
- Choose an action: Format for readable output, Minify for compact output, or Validate to check syntax.
- Review the result in the output pane.
- Click Copy to put the result on the clipboard.
Common uses
- Reformatting auto-generated SOAP responses to make them easier to read
- Pretty-printing SVG files before checking them into version control
- Minifying RSS or Atom payloads to shrink transport size
- Validating configuration files alongside JSON formatter and YAML tools
Technical specification
- Algorithm or formula: The input is parsed with native
DOMParser, then walked node-by-node. A custom indenter re-emits the tree with consistent indentation, preserving CDATA sections, comments, and processing instructions. Minify mode collapses inter-element whitespace. - Browser API or library: Native
DOMParserandXMLSerializerAPIs; no external library. Tree walking viaTreeWalkerorNodeIterator. - Input limits: No hard cap; tested with documents up to 5 MB. Parser errors halt formatting and report the line of the issue.
- Output: Pretty-printed or minified XML, copyable to clipboard or downloadable as
.xml. Validate mode returns success or the first parse error. - Known limitations: The tool cannot repair malformed XML; the document must be well-formed before formatting. DTD validation is not performed.
Frequently asked questions
- Which XML documents does this formatter support?
- Any well-formed XML document, including SOAP envelopes, RSS or Atom feeds, SVG, Maven POMs, Spring or Tomcat configurations, and custom application XML files. CDATA blocks, comments, and processing instructions are preserved. All formatting runs in your browser using the native DOMParser and XMLSerializer APIs.
- Is my XML data sent to a server?
- All processing runs in your browser using the native DOMParser and XMLSerializer APIs. Our servers are not involved at any point.
- Which XML formats are supported?
- Any well-formed XML document, including SOAP envelopes, RSS or Atom feeds, SVG, Maven POMs, Spring or Tomcat configurations, and custom application XML files.
- Can the tool fix malformed XML?
- The tool surfaces parser errors with location details. Malformed documents must be repaired before they can be formatted or minified.
- What is the difference between formatting and minifying?
- Formatting adds indentation and line breaks for readability. Minifying removes inter-element whitespace to make the document as compact as possible for transport or storage.
- Are CDATA blocks and comments preserved?
- Yes. The walker emits CDATA sections, comments, and processing instructions alongside elements so the structure of the original document is maintained.
Reviewed and tested May 26, 2026.