JSON formatter and validator
Format, check and minify JSON safely. Your data never leaves your device.
- Your text is never uploaded
- Processed on your device
- Works offline
- Free, no sign-up
Empty
Result updates as you type
The result appears here as soon as you type or open a file.
Settings
How it works
Paste or open JSON
Paste JSON from an API, a log or a config file, or open a .json file.
Format, check or minify
Valid JSON is formatted at once. If there is a mistake, you see the line and column and what is wrong.
Copy or download
Copy the result or download it as a .json file.
Find mistakes in JSON quickly
JSON must follow strict rules: keys in double quotes, no comma after the last item, no comments and no single quotes. When the JSON is not valid, the tool shows the line and column of the problem and the text around it, with a mark where it goes wrong.
Format makes JSON easy to read with indents. Minify removes all spaces and line breaks to make it as small as possible. Sort keys puts the keys of every object in A to Z order, which helps when you compare two JSON files.
Safe for API keys and private data
JSON often contains tokens, customer data or internal settings. Online formatters may log what you paste; this one runs only in your browser, so nothing leaves your device. Your JSON is read with the browser's own JSON reader and never run as code.
Questions
Is my JSON uploaded?
No. It is checked and formatted inside your browser. Nothing is sent anywhere.
Are very large numbers kept exactly?
Numbers larger than about 9 quadrillion (2^53) may lose their last digits, because JavaScript stores numbers that way. Keep such numbers as strings if they must stay exact.
Can it read JSON with comments?
No. Comments are not part of standard JSON, so they are reported as a mistake with their position.
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