JSON Formatter & Validator
Free, instant, runs 100% in your browser.
What is a JSON Formatter?
A JSON formatter takes raw, compressed or messy JSON text and turns it into a clean, indented, easy-to-read structure. It is one of the most used tools in every developer's workflow, whether you are debugging an API response, inspecting a config file, or preparing data for a colleague.
This tool also validates your JSON at the same time. If there is a syntax error — a missing comma, an unquoted key, or a trailing comma — it tells you exactly what went wrong, so you can fix it quickly.
How to use this tool
- Paste or type your JSON into the Your JSON box.
- Click Format to indent and beautify, or Minify to compress it into one line.
- Click Validate if you only want to check whether your JSON is correct.
- Use Copy Result to copy the output to your clipboard.
Everything runs locally. Your data is never sent anywhere.
Frequently Asked Questions
Is my JSON uploaded to a server?
No. The tool runs entirely in your browser with JavaScript. Your JSON never leaves your device.
Why does my JSON show as invalid?
Common causes: trailing commas, single quotes instead of double quotes, unquoted keys, or comments inside JSON. The validator will point to the exact error location.
What is the difference between Format and Minify?
Format adds indentation and line breaks to make JSON readable. Minify removes all whitespace to produce the smallest possible payload, which is useful for storage and transmission.
Does it work with large JSON files?
Yes, up to what your browser can comfortably handle. Because processing is local, very large files work better here than on server-based tools.