Pretty-print JSON neatly indented or minify it, optionally sort the keys - all locally in your browser, with no upload.
Running locally on your device ...
Running locally on your device ...
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No re-upload neededThese tools accept .JSON - your file is handed over directly.
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
JSON is the most common format for structured data between programs, but in transit it is often squeezed into a single long line that no human can read. This tool brings it back into shape: it parses the JSON and returns it neatly indented, so nesting, lists and objects are visible at a glance. The other way round you can also minify it - every superfluous space removed - when it should be small and fast to transmit.
You choose the indentation (two or four spaces or a tab) and can have the keys of each object sorted alphabetically. Sorting is useful to make two JSON documents comparable or to produce stable, reproducible output. Because the tool genuinely parses and re-serializes the JSON, the output is always valid JSON; broken input is not silently repaired but reported honestly as an error.
All processing runs entirely locally in your browser in pure JavaScript - your JSON is not uploaded, not stored, and no foreign library is loaded from a CDN. That matters precisely for configurations, API responses or exports, which quickly contain confidential values. You can download the result or copy it straight out.
Many online JSON formatters send your input to their own server to format it - risky when the JSON contains API keys, tokens or customer data, which is common in configurations and API responses. This tool processes your JSON strictly locally, with no account, no character limit and no ads in the result - on any device with a modern browser.
| Input formats | Text input |
|---|---|
| Output format | JSON |
| Batch processing | No |
| Processing | Locally in your browser (JavaScript) |
| File upload | None |
Limitations: The tool reformats valid JSON per RFC 8259; it does not repair broken syntax or add missing quotation marks. Comments are not allowed in JSON and lead to an honest error. Very large documents are limited by your device memory. The order of array elements is always preserved; only object keys are sorted.
No. Formatting runs entirely locally in your browser; your data never leaves your device and is not stored.
Indenting makes the JSON readable for humans (line breaks and spacing). Minify removes all superfluous characters so it becomes as small as possible - ideal for transmission, poor for reading.
Sorted keys make two documents easier to compare (diff) and produce a stable, reproducible order. The values and the order of lists stay unchanged.
The tool reports an honest error instead of inventing a wrong result or silently changing the input.
Yes, in any current mobile browser just like on desktop - the JSON stays local on the device.
No. No account and no artificial character limit - only your device memory sets a boundary for very large documents.
Yes. Unlike many online formatters, your JSON is not sent to a server - try airplane mode, formatting keeps working.