JSON / YAML / XML Converter

Choose an input and output format to convert in any of the six directions. JSON is common in APIs, YAML in configuration files, and XML in structured documents. This tool converts supported data structures; it does not validate an API contract, application configuration or XML schema.

Processing takes place in your browser. The conversion feature does not upload, save or reuse your input. Shared page resources, analytics and advertising may still use the network.

The tool uses eemeli/yaml with YAML 1.2 support and a limited XML 1.0 parser. Select compact output or indentation of two or four spaces. Swap uses a successful result as the new input; an invalid draft is retained when formats change.

Input and output are each limited to 200,000 UTF-16 code units, nesting depth to 64, and data to 50,000 values. Some characters, including many emoji, count as two code units. Circular aliases, unsupported YAML tags, non-string YAML keys and duplicate JSON keys are rejected. Aliases are also subject to the parser's expansion limit.

Numbers whose decimal value or sign would change during conversion are rejected, as are non-finite numbers and integers outside JavaScript's safe range. This is not an arbitrary-precision converter. Use quoted strings when the exact representation is part of the data, such as an identifier.

Attributes become keys such as @id, mixed text is stored in #text, and repeated children with the same name become an array. XML text and attributes become strings: number and boolean types are not restored. In the reverse direction, attributes must be strings, numbers or booleans.

Empty arrays, empty objects and null become empty elements. A one-item array cannot be distinguished from a single value. Nested arrays are rejected. One ordinary top-level key with a non-array value names the root element; array-valued keys, multiple keys and objects containing only @attributes or #text are wrapped in root. A root array becomes root/item.

Comments, formatting-only whitespace between child elements, mixed-content order and ordering across different child names are lost. Whitespace explicitly represented by character references or CDATA and leading/trailing whitespace in leaf elements are preserved. Indentation is not added inside mixed text.

DOCTYPE, ENTITY declarations, processing instructions, namespace prefixes and names or characters outside the supported XML 1.0 rules are rejected. Reserved XML namespace URIs cannot be used as the default xmlns namespace. Namespace-prefixed SOAP documents are therefore outside this tool's scope. Inspect converted data before using it elsewhere.