Glossary Data & Encoding

JSON

JSON (JavaScript Object Notation) is a lightweight text format for structured data, built from objects, arrays, strings, numbers, true, false and null.

Last reviewed: 2026-10-03

In more detail

Keys and strings must use double quotes, and comments and trailing commas are not allowed, which are the usual causes of "invalid JSON" errors. JSON is the usual format for web APIs and configuration files.

Example

{"name": "Ana", "age": 30, "tags": ["a", "b"]} is a valid JSON object.

Try these tools

JSON Formatter & Prettifier

Prettify and format messy JSON instantly.

JSON Validator & Online Debugger

Check if your JSON is valid according to RFC 8259 standards.

JSON Schema Validator

Paste a schema and a JSON document to check types, required properties, enums, formats, patterns, $ref and combinators.