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Definition

What is JSON (JavaScript Object Notation)?

JSON is a lightweight, text-based data format that represents objects, arrays, strings, numbers, booleans, and null — the default wire format of the web.

Also called: JavaScript Object Notation · .json

JSON was derived from JavaScript syntax in the early 2000s and standardised as ECMA-404 and RFC 8259. Every major programming language has a built-in parser.

It's the default request and response body for REST APIs, the default document shape in MongoDB and Elasticsearch, and the default config format for Node.js, VS Code, and countless CLIs.

JSON has no comments, no trailing commas, and no dates — those are string conventions on top. Strict parsers reject anything that isn't literal JSON, so a formatter/validator is the first stop when a payload breaks.

Try a tool that uses JSON (JavaScript Object Notation)

JSON Formatter

Format, indent, and pretty-print JSON instantly in your browser.

JSON Validator

Validate JSON syntax and pinpoint parse errors line by line.

XML Formatter

Pretty-print and indent XML documents with nested elements.

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