JSON Formatter & Validator
Beautify, minify and validate JSON with clear error messages.
- Free, no sign-up
- Files stay on your device
- Works offline
How to use the JSON Formatter & Validator
- 1
Paste your JSON into the input box, or click “Sample” to try an example.
- 2
Choose an indentation and click “Format” to beautify, or “Minify” to compress it.
- 3
If the JSON is invalid, the error message shows the line and column to fix.
- 4
Copy the result or download it as a .json file.
Frequently asked questions
Everything you need to know about the JSON Formatter & Validator.
Is my JSON sent to a server?
No. Formatting and validation happen entirely in your browser, so it is safe to paste API responses, configs and other private data.
Why is my JSON invalid?
The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys and comments. JSON allows none of these.
What is the difference between formatting and minifying?
Formatting adds line breaks and indentation so JSON is easy to read. Minifying removes all unnecessary whitespace to make the file as small as possible.
Is there a size limit?
There is no fixed limit. Files of several megabytes format instantly on most devices.