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What Is JSON? A Beginner's Guide to Reading and Fixing It

Learn what JSON is, its basic rules, and how to validate and format it in seconds.

By the ToolWorlds team · Updated 2026-10-29

What JSON is

JSON is a simple text format for storing and sending data. Websites and apps use it to talk to each other. It is built from objects, written inside curly braces with named values, and lists, written inside square brackets.

{"name":"Sara","age":24,"skills":["design","writing"],"active":true}

The basic rules

How to check and format it

  1. Open the JSON Formatter and paste your data.
  2. Press Validate. A green message means it is valid; otherwise the error tells you what to fix.
  3. Press Format to add indentation, which makes the structure easy to read.
  4. Press Minify when you need a compact one-line version to send.

Most common mistakes

A trailing comma, single quotes instead of double quotes, and names without quotes cause most errors. Fix one, validate again, and repeat. If JSON travels inside a link, encode it first with the URL Encoder, and if it must travel as plain text, the Base64 Encoder can help.

Try it now: JSON Formatter & Validator – Format, minify and validate JSON online with clear error messages.

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