Format & validate JSON, stay local
Paste or drop a JSON file. Get pretty-print, minify, sort keys and a tree view. Error positions are reported when parsing fails.
✦ Pretty & minify✦ Sort keys✦ Tree view✦ No uploads
Input
Idle
Output
Ready
FAQ
About JSON formatting
Do you upload my JSON?
No. Formatting, validation and tree-building all run in your browser. Your data is not transmitted.
How are parse errors shown?
When the input isn't valid JSON, the status line shows the error message and the position (line/column) reported by the browser's JSON parser.
What's the largest input you accept?
There's no fixed limit — your device's memory sets the practical limit. Multi-megabyte JSON files work fine on modern hardware.