XML Formatter
Why use a private XML formatter?
XML is still the wire format for a huge amount of enterprise software — SOAP APIs, Maven POM files, Android manifests, SVG, Office Open XML, and countless config systems. Pasting these into an online formatter means sending potentially sensitive payloads — API responses, credentials in config attributes, internal service addresses — to a third-party server.
formatvault formats and validates XML entirely inside your browser using fast-xml-parser. Nothing is transmitted. The network tab will show zero outbound requests while you work.
How it works
Your XML is parsed into an in-memory tree using fast-xml-parser, then re-serialized with consistent indentation. Attributes, CDATA sections, and comments are preserved through the round-trip. The XMLValidator checks well-formedness before formatting so you get a precise error with line and column numbers before any output is produced.
Minify mode strips all non-significant whitespace for smaller payloads. Validate mode checks only well-formedness without modifying the input — useful as a quick sanity check before committing a config file.
Common use cases
- Formatting SOAP request/response bodies from API testing tools
- Validating Android AndroidManifest.xml and layout files before building
- Pretty-printing Maven pom.xml files with deeply nested dependency trees
- Debugging minified XML payloads from enterprise integrations (SAP, Salesforce)
- Formatting SVG files exported from Figma or Illustrator for readability
- Normalising Office Open XML (.docx/.xlsx internals) for inspection
- Minifying XML config files before bundling into a deployment artifact
- Checking well-formedness of RSS or Atom feed XML
Frequently asked questions
- Is it safe to format XML that contains sensitive data?
- Yes. All processing happens in your browser using fast-xml-parser — your XML is never sent to any server. You can verify this by opening DevTools → Network and observing zero outbound requests when you format.
- What does "validate" check?
- The validator checks that your XML is well-formed: proper tag nesting, closed tags, valid attribute syntax, and legal character encoding. It does not validate against an XSD or DTD schema — that would require a schema file.
- Does the formatter preserve comments and CDATA sections?
- Yes. Comments and CDATA sections are preserved through the parse-and-rebuild cycle. Attributes are also preserved with their original values.
- What is the difference between formatting and minifying?
- Formatting adds consistent indentation and newlines to make the XML human-readable. Minifying removes all non-significant whitespace to produce the smallest possible output, useful for reducing payload sizes.
- Does it work offline?
- Yes, once the page has loaded. The fast-xml-parser library is bundled with the app and requires no network access to format or validate XML.