2026-01-18

By JW Tool Box

XML to JSON Converter: Attributes, Types and API Mapping Checks

Last updated 2026-10-31T00:00:00.000Z

Inspect how XML maps into JSON before using the result in an API. Format conversion is only one step in a data migration.

Use XML/JSON Converter to convert pasted XML into JSON or JSON into XML. Select a direction, paste the input, convert, then copy the output. The interface does not fetch a feed URL or import a file for you.

A converted SOAP envelope is still an envelope-shaped object. It is not automatically a REST endpoint, a valid target API payload or a complete migration.

Checked XML-to-JSON example

The following example was checked against the installed parser with the same options the tool uses: attributes are enabled and prefixed with @_.

<user id="007"><age>30</age><active>true</active><middleName/></user>

Current result:

{
  "user": {
    "age": 30,
    "active": true,
    "middleName": "",
    "@_id": "007"
  }
}

Notice three distinctions: the attribute remains a string, numeric and boolean element values are parsed into their corresponding types, and the empty element becomes an empty string rather than null. Check identifiers and values whose exact lexical spelling matters. The interface has no option to force every element value to remain a string.

Repeated tags and single items have different shapes

<items><item>A</item><item>B</item></items>

Produces:

{ "items": { "item": ["A", "B"] } }

With only one item, the current result is instead:

{ "items": { "item": "A" } }

A downstream API expecting an array may therefore require normalization. Test both one-item and multiple-item cases; there is no always-array checkbox in the current interface.

Attributes and namespace prefixes

Attributes use the @_ prefix. Namespace declarations can appear as attribute keys, and qualified element names can retain their prefixes. This is a representation of the input, not schema-aware namespace validation or a mapping to your API's field names.

Copy only the required values into an explicitly designed target payload. Check required fields, types, optional fields and collection shapes rather than sending the entire converted envelope unchanged.

Mixed text is not a lossless round trip

With the current parser options:

<text>Hello <b>world</b> again</text>

Produces:

{ "text": { "b": "world", "#text": "Helloagain" } }

Text placement and spacing are not preserved as an ordered document model. Do not use this conversion as a lossless editor for narrative XML, signed XML or documents whose mixed-content order matters. Keep the original.

Convert JSON back to XML

Select JSON → XML, then paste:

{ "user": { "name": "Ada", "@_id": "007" } }

The current builder produces:

<user id="007">
  <name>Ada</name>
</user>

The direction-swap control uses the current output as the next input. Inspect that output before swapping. A successful reverse conversion does not establish equivalence to the original XML document.

Validation and failure checks

• Use syntactically valid input. The tool does not run an XML schema validator; a successful parse is not proof of a valid business document or schema.
• Test empty elements, repeated tags, attributes, mixed content and numeric-looking identifiers with a small sample.
• Check the copied output in the actual receiving application. Clipboard access can be denied; manually select the output if needed.
• Keep large-file expectations conservative. The interface provides no streaming mode or tested multi-megabyte capacity guarantee.
• Do not assume offline availability from a prior visit. Required assets must already be available, and offline behavior has not been newly verified here.

Pasted data is processed locally by the browser tool rather than uploaded to JW Tool Box. Analytics and advertising are described separately in the Privacy Policy. Use synthetic examples when reporting a problem.