What is JSON?

JSON (JavaScript Object Notation) is a lightweight, text-based format for representing structured data as key–value pairs and arrays. It is the de facto standard for web APIs and configuration because it is both human-readable and easy for machines to parse.

Despite the name, JSON is language-independent and supported everywhere. It represents objects, arrays, strings, numbers, booleans, and null.

Key points

  • Represents objects, arrays, strings, numbers, booleans, and null.
  • Keys must be double-quoted strings.
  • No comments or trailing commas are allowed.
  • Language-independent despite the JavaScript name.

Example

{ "name": "Ada", "active": true, "roles": ["admin"] }

Common uses

  • Request and response bodies in web APIs
  • Configuration files (package.json, tsconfig.json)
  • Storing and exchanging structured data
  • NoSQL document storage

Work with JSON directly in your browser.

Open the JSON Formatter

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