DataToolsLab

The Ultimate JSON Guide

A practical guide to JSON: types, parsing, common errors, and tools.

JSON powers nearly every web API. This guide covers validation, formatting, and how to move data between JSON and other formats.

What is JSON?

JSON (JavaScript Object Notation) is a text format with two structures: a collection of key/value pairs (object) and an ordered list of values (array).

Types

JSON supports strings, numbers, booleans, null, objects, and arrays. There is no date type — use ISO 8601 strings instead.

Validation

Use an online validator (or a strict parser in your language of choice). Our CSV-to-JSON tool is a quick way to verify a JSON output structure.

Related tools

Online