🧩 JSON Formatter & Validator — Beautify JSON Online

Tidy up messy JSON or shrink it — with error messages.

Paste JSON: Format makes it beautiful (pretty-print), Minify makes it compact. If there is an error, the exact error is shown.

How to Use?

  1. Paste your JSON.
  2. Press Format or Minify.
  3. Read the error if any, or copy if correct.

What Is JSON?

JavaScript Object Notation — the most common format for sending data (APIs, configs). Keys are always in double quotes.

Frequently Asked Questions

What is the most common JSON error?
A trailing comma (a , after the last item) or using single quotes.
Why minify?
To make the file smaller — the website loads faster.
Is my data saved?
No, everything happens in the browser.

Last updated: 30 September 2026 · Category: Developer Tools