YAML to XML Converter

What does this tool do?

It converts a YAML document into XML, with several options to control exactly how the conversion maps YAML's structures onto XML elements — since XML has no native concept of "list" the way YAML does, arrays need an explicit strategy.

How this tool works

1. Paste your YAML into the input box.
2. Set a root element name for the generated XML's outermost tag.
3. Choose how arrays should convert: repeated elements wraps each array item in a singularized version of its parent key (features → <feature>...</feature> repeated), or indexed appends a numeric suffix (feature_0, feature_1, ...).
4. Choose how null values should render: an empty element (<key/>), omitted entirely, or marked with an xsi:nil="true" attribute (adding the standard XML Schema instance namespace).
5. Optionally wrap string values in CDATA sections, toggle the XML declaration, and set the indentation.

The Summary table reports the element count, maximum nesting depth, and output size — useful for sanity-checking a large conversion.

Element name sanitization

YAML keys can contain characters that aren't valid in XML element names (spaces, symbols, a leading digit). Any such key is sanitized: invalid characters become underscores, and a name that doesn't start with a letter or underscore gets one prepended.

Mixed-type array warning

If an array mixes types (e.g. some string items and some numbers), the summary flags it — XML doesn't preserve JavaScript's type information the way YAML/JSON do, so mixed-type arrays are exactly where information is most likely to get lossy in the round trip.

Common uses

• Converting a YAML configuration file to XML for a system that only accepts XML
• Migrating data between YAML-based and XML-based APIs or pipelines
• Exploring how different array-handling strategies affect XML output shape
• Generating XML test fixtures from hand-written YAML

Privacy

This tool runs entirely in your browser. Your data is never uploaded to a server.