Online JSON Formatter & Validator

This JSON formatter makes data readable with two-space indentation, produces a compact version for transfers, and validates the structure before you use it. When the JSON is broken you get the browser’s exact error message, so a trailing comma, a missing quote or an unclosed brace is quick to find. It suits reading API responses, tidying config files and preparing test data, and no data leaves your browser.

This tool runs entirely in your browser. No data is sent to any server.

How to use it

1. 1

   Paste or type your JSON into the box.

2. 2

   Press Beautify for readability, Minify for a smaller payload, or Validate to check the structure.

3. 3

   If something is wrong the exact message appears below the box; copy the result into your project.

Frequently asked questions

What is the difference between beautify and minify?

Beautify adds indentation and line breaks for human reading; minify strips unnecessary whitespace to reduce the payload size.

How do I find the JSON error?

Press Validate. The browser message usually points at the line or character that broke the structure.

Does it handle large files?

As far as your browser memory allows. Files of several hundred megabytes can make the tab slow.