// free · runs in your browser · nothing uploaded
JSON Minifier: Compress JSON to One Line
Remove spaces and line breaks to make JSON as small as possible. See the size before you copy or download it.
📚 Official sources: JSON standard (RFC 8259)
We build every tool from the official rules and re-check them when they change. Always confirm with the official source before you rely on a result.
🛠️ Spotted a mistake or an out-of-date rule? Tell us
Questions people ask
Is my JSON uploaded anywhere?+
No. The formatter uses your browser's own JSON parser, so your data never leaves your device. You can even use it offline once the page has loaded.
Why does it say my JSON is invalid?+
The most common causes are a comma after the last item in an object or array, single quotes instead of double quotes, keys without quotes, and comments. Standard JSON (RFC 8259) allows none of these. The tool shows the line and column where the problem starts.
What is the difference between formatting and minifying?+
Formatting (beautifying) adds line breaks and indentation so people can read it. Minifying removes all spaces and line breaks so the file is as small as possible for sending over a network. The data itself does not change.
Does sorting keys change my data?+
No. Objects in JSON have no fixed key order, so sorting keys A–Z only changes how it looks. Array order is never changed.