JSON to XML

Paste JSON on the left and XML appears on the right. A key beginning with @ is written as an attribute, a key called #text becomes the element's own text, and an array repeats its element.

Root element is used when the JSON needs a wrapper. If your JSON has exactly one key at the top, that key is the root and the setting is ignored, since inventing a second wrapper round it would change the shape for no reason.

This is the constraint that shapes everything else. An XML document has one outermost element, always. JSON has no such rule: a file can be an array, a number or a bare string, and plenty are.

So a wrapper sometimes has to be invented, and an invented name is a decision the converter is making on your behalf. The setting exists so it is your decision instead.

Names have rules too. An XML element name cannot start with a digit and cannot contain a space, so a JSON key like "first name" or "2024" is rewritten into something legal. Check the output if your keys came from a spreadsheet header.

The JSON licence, written by Douglas Crockford for his own Java implementation, is the MIT licence with one sentence added: "The Software shall be used for Good, not Evil."

It caused real trouble. The clause makes the licence non-free by the usual definitions, because it restricts the field of use, so Debian and the Free Software Foundation both treat it as unusable. Apache told its projects to stop shipping the code. Companies wrote to Crockford asking for an exemption, and he has said IBM's lawyers got a letter back giving their customers permission to use it for evil.

The clause is still there. JSON itself carries no such condition, since a data format cannot be licensed; only Crockford's implementation of it can.

XML to JSON is the other direction, and explains why no single mapping between the two is correct. JSON to YAML is a gentler reformatting, since YAML can already hold everything JSON can.

To flatten a list of objects into rows instead, use JSON to CSV.