JSON Formatter
Format and pretty-print JSON with 2 or 4 spaces or tabs. Errors point to the exact line and column with a plain-English hint.
Free · No upload · 100% on your device
How to use JSON Formatter
- Type or paste your code or data, or open a file.
- Choose the settings in the side panel. The result updates as you type.
- Copy the result or download it as a file.
Private by design. Everything you type, open or record is processed in this browser tab and is never uploaded to KittySuite.
About JSON Formatter
Paste minified JSON from an API or a log and it is indented instantly. If the JSON is broken, the message shows where the parser stopped and common causes such as single quotes or a trailing comma. Large files of several megabytes work too.
Everything runs in this browser tab: your text is never uploaded or stored, and the result updates as you type. It keeps working offline once the page has loaded.
JSON Formatter: frequently asked questions
How do I format JSON online?
Paste the JSON or open a .json file. It is indented instantly with 2 or 4 spaces or tabs.
What happens if my JSON has an error?
The message shows the line and column where parsing stopped, with a plain-English hint about common causes such as single quotes or a trailing comma.
Can I format large JSON files?
Yes. Files of several megabytes work; the limit is your device’s memory.
Is my JSON sent to a server?
No. It is processed in this browser tab and never uploaded, which matters for API responses, logs and exports that contain private data.