What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based format for storing and exchanging data. It is easy for humans to read and write and easy for machines to parse and generate, which is why it is the default data format for web APIs, config files, and countless tools.

What JSON looks like

JSON is built from two structures — objects ({ }, key/value pairs) and arrays ([ ], ordered lists) — holding four value types: strings, numbers, booleans (true/false), and null.

{
  "name": "Ada Lovelace",
  "born": 1815,
  "fields": ["mathematics", "computing"],
  "active": false,
  "notes": null
}

Try it

Paste any JSON below to format, validate, or convert it:

The official JSON standard

JSON was specified by Douglas Crockford in the early 2000s and later standardized twice, identically: as ECMA-404 and as IETF RFC 8259. The canonical one-page grammar lives at the official site, json.org.

• json.org — official site
• RFC 8259 — IETF standard
• ECMA-404

Frequently asked questions

Who invented JSON?

Douglas Crockford specified and popularized JSON in the early 2000s, drawing on JavaScript's object literal syntax. It was standardized as ECMA-404 (2013) and RFC 8259 (2017).

Is JSON the same as a JavaScript object?

No. JSON is a text format inspired by JavaScript object syntax, but it is language-independent and stricter: keys must be double-quoted strings, no trailing commas, no comments, and no functions or undefined.

What is the official JSON spec?

The grammar at json.org, formalized as ECMA-404 and RFC 8259. All three describe the same format.