JSON to XML Converter

Understand this converter’s JSON-to-element mapping

JSON and XML do not share a single official conversion standard. Objects have named properties, arrays have ordered values, and XML has elements, attributes, namespaces, and text nodes. This JSON to XML converter uses a compact, element-only mapping designed for quick examples: object keys become tag names, primitive values become text, nested objects become nested elements, and arrays repeat an element named after the array property.

The result updates whenever the JSON input changes. A valid conversion appears in Converted Output and can be copied. Invalid JSON displays Error: followed by the parser message in that same output area. There are no mapping options, pretty-print controls, file downloads, XML declaration settings, or custom root-name fields.

How the root element is chosen

The converter reads the first key of the parsed root object and also serializes the entire object inside a root tag with that name. This has a notable consequence: the first property commonly appears twice, once as the wrapper name and once as its child.

For example:

{
  "user": {
    "name": "Jane"
  },
  "active": true
}

produces:

<user><user><name>Jane</name></user><active>true</active></user>

This is the implemented output, not the alternative <user><name>Jane</name><active>true</active></user> that another conversion convention might choose. If the consuming system requires a specific XML contract, review and adapt the copied result rather than assuming a standard mapping.

When the root object has no keys, the fallback wrapper is <root></root>. Root arrays and primitives are not handled meaningfully by the serializer because it expects enumerable object properties. Use a root object with XML-safe keys for predictable results.

Map nested objects and scalar values

For each object property, a non-null object is processed recursively. Strings, numbers, booleans, and null become text between an opening and closing element named after the property. JavaScript string conversion is used, so booleans appear as true or false, numbers use their ordinary textual form, and null appears as null.

Input:

{
  "service": {
    "name": "orders",
    "port": 8080,
    "enabled": true,
    "owner": null
  }
}

Output:

<service><service><name>orders</name><port>8080</port><enabled>true</enabled><owner>null</owner></service></service>

The XML is emitted on one line with no declaration and no indentation. The output text area may wrap visually, but those wraps are not inserted as formatting.

How arrays are represented

An array property is iterated in order. For every item, the serializer creates an element with the array property’s key. It passes an object shaped like { item: value } into that repeated element.

For primitive array values:

{
  "catalog": {
    "skills": ["JavaScript", "React"]
  }
}

the relevant output is:

<skills><item>JavaScript</item></skills><skills><item>React</item></skills>

For object items, another nesting layer appears:

{
  "catalog": {
    "products": [
      { "id": 1, "name": "Pen" },
      { "id": 2, "name": "Book" }
    ]
  }
}

Each product is wrapped as a repeated <products> containing <item>, which then contains the object’s fields. Empty arrays produce no element at all, so the output cannot distinguish an empty array from a missing property.

Nested arrays produce further element layers according to the same recursion. There is no option to choose singular item tags, container tags, or attributes.

Convert a document in the interface

1. Replace the preloaded user example in Input Format with a valid JSON object.
2. Read the generated XML in Converted Output. The conversion runs automatically; no button is required.
3. If the panel begins with Error:, fix the JSON syntax in the left editor.
4. Select Copy after successful output. The button shows Copied briefly.

Copy is disabled while an error exists or the output is empty. Both editors have fixed working heights and the output is read-only. The input has no separate Clear or Load Sample control, although the initial sample can be selected and replaced normally.

Appropriate use cases

Sketch an element hierarchy

The output gives a quick starting point when translating a simple object-shaped example into XML-like elements. It can help communicate nesting in a prototype before a formal XML schema has been defined.

Prepare a minimal integration sample

For a system that accepts straightforward element-only XML and controlled alphanumeric keys, convert a small payload and inspect every tag. Add any required declaration, namespace, wrapper, and escaping afterward.

Compare format concepts

The direct mapping demonstrates why JSON-to-XML conversion needs policy decisions: arrays need an item convention, null needs a representation, and a root must be selected. It is useful for teaching those differences precisely because the mapping is visible.

Bootstrap test text

Copy the result into a test fixture for a parser prototype, then adjust it to the target contract. Do not use generated XML as a conformance fixture until it has been validated by the relevant XML parser or schema.

Critical escaping and tag-name limitations

The serializer inserts keys directly into tag names and values directly into element text. It does not escape XML special characters. A string containing &, <, or > can produce malformed XML or unintended markup. Quotes matter less in text nodes but would need escaping if later moved into attributes.

For example, {"message": "A < B & B > 0"} is inserted literally rather than converted to A < B & B > 0. Treat this as unsafe for arbitrary or untrusted strings. Escape values with an XML-aware library before use.

JSON keys can also be invalid XML element names. Spaces, some punctuation, a leading digit, or namespace-like colons may violate the rules expected by an XML parser. The converter neither sanitizes nor rejects such keys. Sanitizing automatically could create collisions, so production conversion should use an explicit mapping.

Troubleshooting conversion problems

The output repeats the first key

That follows the root algorithm: the first root key names the wrapper, and then all root properties, including that first key, are serialized as children. Manually restructure the input or edit the XML if the target contract expects another root layout.

The XML parser rejects copied output

Look first for unescaped & and < in values, then for invalid element names derived from JSON keys. Also check whether the destination requires an XML declaration, namespace, encoding declaration, or a specific root element.

Array items have unexpected wrappers

The implemented convention repeats the array key and nests each value under <item>. There is no setting to change this. A contract-specific converter is needed for alternate container/item names.

The panel shows a JSON parse error

Remove comments and trailing commas, use double-quoted keys and strings, and balance every brace and bracket. Conversion begins only after strict JSON parsing succeeds.

Empty arrays disappeared

No iterations means no emitted array tags. If emptiness must be explicit, map the data manually to the XML convention expected by the consumer.

The output has no line breaks

The serializer produces compact XML. It has no indentation option or XML formatter stage.

What is not represented

The converter creates elements only. It does not produce attributes, CDATA, namespaces, comments, processing instructions, entity declarations, mixed content, an XML declaration, or schema-instance annotations. It has no special date, binary, or null encoding and does not validate the resulting text as XML.

Conversion is not reliably reversible. Empty arrays can disappear, primitive types become text, and the root convention adds structure. Duplicate JSON keys are already lost during parsing. Browser memory limits very large documents, and the synchronous recursion is best suited to modest payloads.

Use an XML library and an explicit mapping for feeds, SOAP messages, signed XML, namespace-heavy formats, security-sensitive input, or any contract governed by XSD.

JSON to XML FAQ

Does the result include <?xml version="1.0"?>?

No. The output begins directly with its generated root element.

Are values XML-escaped?

No. Special characters are inserted literally. Inspect and escape them before treating the result as valid XML.

Can I map properties to attributes?

No. Every key is used as an element name.

What happens to arrays?

The array key is repeated once per value, and each repeated element contains an <item> representation. Empty arrays emit nothing.

Can I select the root tag?

No. It uses the first key of the parsed root object, falling back to root when there is no key.

Does it pretty-print XML?

No. Generated XML is compact and single-line.

Can I download an XML file?

The current interface supports clipboard copying, not downloading.

Is the output guaranteed to be valid XML?

No. Invalid tag names and unescaped values can make it malformed, and no XML parser is run. Validate and transform it according to the receiving system’s requirements.