What is JSON? A Beginner's Guide
June 12, 2026 · By Toolzy Team
JSON in one sentence
JSON (JavaScript Object Notation) is a lightweight, human-readable format for storing and exchanging data.
The building blocks
- Objects
{ }hold key–value pairs - Arrays
[ ]hold ordered lists - Values can be strings, numbers, booleans, null, objects or arrays
{
"name": "Toolzy",
"tools": 100,
"free": true
}
Common mistakes
- Trailing commas are not allowed
- Keys must use double quotes
- No comments permitted
Paste your JSON into the JSON Formatter to beautify it and catch errors instantly.