CaseWren

JSON Formatter & Validator

Format, validate and minify JSON with error positions.

0 Characters
Output
Formatted output appears here…

About the JSON Formatter & Validator

Minified API responses are unreadable, and a single missing comma can burn twenty minutes of debugging. Paste your JSON here to validate it live — invalid input is flagged with the parser's exact error position — then pretty-print with a 2- or 4-space indent, or compress it back down for production.

Everything runs locally in your browser, so it is safe for API responses containing tokens or user data you would never paste into a server-side formatter.

How to use it

  1. 1Paste JSON into the input — the validity badge updates as you type.
  2. 2Click Format · 2 spaces or Format · 4 spaces to pretty-print, or Minify to compress.
  3. 3Copy the output; if there is an error, use the position info to fix it.

Frequently asked questions

Related tools

Search CaseWren tools

Search all 147 tools…