JSON Formatter — Beautify, Minify, and Validate JSON Online

What is this JSON Formatter?

A free, fast JSON tool that runs entirely in your browser. It supports three core operations: beautify (pretty-print with customizable indentation), minify (compress to one line), and validate (catch syntax errors with line numbers). Your JSON never leaves your device — perfect for sensitive API responses, config files, or token fragments.

How to use it

1. Paste your JSON into the input box (drag-and-drop a file works too)
2. Click "Beautify" (2 / 4 spaces or Tab) or "Minify" depending on your goal
3. Read the formatted output; click "Validate" to check for syntax errors

Common use cases

• Debugging REST API responses outside of Postman or cURL
• Compressing JSON config files before deployment to reduce payload size
• Validating teammate-submitted JSON during code review
• Restoring readability of minified JSON from production bundles

FAQ

Q: Does my data get uploaded to a server?
A: No. Everything runs locally in your browser via JavaScript.

Q: Does it support JSON5 or commented JSON?
A: Strict standard JSON only. For commented JSON, run it through a cleaner first.

Q: Is there a file size limit?
A: Bounded by browser memory. Files under 10 MB are usually smooth.

Tips

• Combine with the "JSON to CSV" tool to export API data into Excel
• Pair with "JSON ↔ YAML" to convert between K8s/Docker config formats