JSON formatter and validator
Paste JSON to tidy it, minify it or find what is wrong with it. Errors point to the line and column and say what usually causes them, and numbers and strings are kept exactly as written.
S'exécute entièrement dans votre navigateur — rien n'est envoyé nulle part
S'exécute entièrement dans votre navigateur — rien n'est envoyé nulle part
The mistakes that break JSON most
- A comma after the last item: [1, 2, ].
- Single quotes, or keys without quotes, copied from JavaScript.
- Comments, which configuration files often have and JSON does not allow.
- True, None or undefined, copied from Python or JavaScript, instead of true and null.
Why keep numbers exactly?
Most formatters parse with JavaScript, which turns 12345678901234567890 into 12345678901234567000 and 1.50 into 1.5. This formatter never converts values, so what you copy out is what you pasted in, only laid out differently.
Does it accept comments or trailing commas (JSON5)?
No — it checks strict JSON as APIs and parsers expect it, and tells you exactly where those extensions are, so you can remove them.
Is my JSON sent anywhere?
No. It is parsed in your browser and nothing is stored.