toolready

JSON Formatter & Validator

Pretty-print, minify, and validate JSON with precise error pointers.

What this does

Paste JSON in, get it pretty-printed (formatted), minified, or validated. When the input is invalid, you'll get an inline error pointing to the line and column of the first problem — no more squinting at "Unexpected token at position 1832".

How to use it

  • Format — pretty-prints with your chosen indent (2 spaces, 4 spaces, or tab).
  • Minify — collapses to a single line, shortest possible.
  • Validate — just tells you if it parses, useful for quick checks.

What counts as valid JSON?

  • Strings must use double quotes, not single.
  • No trailing commas (after the last item in an array or object).
  • Keys must be strings in double quotes.
  • No comments (use JSONC or JSON5 if you need them).
  • Top-level value can be an object, array, string, number, boolean, or null.

Is my data private?

Yes. Parsing and formatting happen entirely in your browser via the built-in JSON.parse / JSON.stringify. Nothing leaves your device. Safe to paste production payloads, API responses, secrets, anything.