JSON Formatter & Minifier
A free, browser-based file tool. Runs entirely in your browser — no sign up, nothing stored.
100% FreeRuns in your browserBasic
Runs entirely in your browser — nothing is uploaded or stored.
How to use this calculator
- Paste your JSON.
- Press Format to pretty-print, or Minify to compress.
How it works
Format indents the JSON so it's readable; Minify strips all whitespace to make it as small as possible. Both validate the JSON and report the first error.
Frequently asked questions
Why won't my JSON format?
It must be valid JSON — keys and strings need double quotes, and there can be no trailing commas.
Related tools
Tip: Enter any known values to calculate the remaining results.
All calculations run in your browser. Your inputs are never saved or transmitted.