XML to JSON Converter

XML has elements, attributes, text and order; JSON has objects, arrays and values. There is no single official mapping, so this is what the converter does with the default options:

Other tools follow similar rules with different names. Python's xmltodict and Json.NET both use @ for attributes and #text for text, so the defaults here produce the same shape. yq uses its own attribute prefix and puts text under +content; both can be changed with flags.

• Feeding a typed client or a schema? Turn on Always use arrays. Then order.items.item is always an array, even when an order has one item, and your code needs no special case.
• Matching Python or .NET output? Keep the @ prefix and #text. That is the xmltodict and Json.NET convention.
• PHP-style output? Choose Grouped. Each element gets an @attributes object, like PHP's json_encode(simplexml_load_string($xml)) produces.
• Only want the data? Choose Ignore for attributes and turn on Strip namespaces. SOAP and RSS responses get much shorter.
• Need exact text? Turn off Numbers and booleans so every value stays a string, as it was in the XML.

JavaScript and Node.js with fast-xml-parser (the library this page uses):

import { XMLParser } from "fast-xml-parser";

const parser = new XMLParser({
  ignoreAttributes: false,
  attributeNamePrefix: "@",
  isArray: (name) => name === "item",   // force arrays for chosen elements
});
const json = JSON.stringify(parser.parse(xml), null, 2);

Python with xmltodict, and back again with unparse():

import json, xmltodict

data = xmltodict.parse(xml, force_list=("item",))   # attributes as @key, text as #text
print(json.dumps(data, indent=2))

xml_again = xmltodict.unparse(data, pretty=True)

Command line with yq:

yq -p xml -o json input.xml > output.json
yq -p json -o xml input.json > output.xml

C# with Json.NET:

var doc = new XmlDocument();
doc.LoadXml(xml);
string json = JsonConvert.SerializeXmlNode(doc, Formatting.Indented);
XmlDocument back = JsonConvert.DeserializeXmlNode(json);

Going the other way, some JSON has no direct XML form. The converter handles these cases and tells you what it changed:

• Several top-level keys, or a top-level array. XML needs one root element, so the JSON is wrapped in <root> (rename it in the options). Array entries become <item> elements.
• Keys that are not valid XML names. Names cannot contain spaces or start with a digit, and names starting with "xml" are reserved. first name becomes first_name and 1st becomes _1st.
• Special characters. &, < and > in values are escaped, so the output is always well-formed.
• null. Becomes an empty element, <key/>.

To check or pretty-print the result, open it in the XML formatter and validator. For other formats, try YAML to JSON or JSON to CSV, and browse API tools on DevHunt.