JSON Formatter — what it does
Turns a wall of minified JSON into something you can actually read — or the reverse, when you need to ship it. Indentation is configurable (2 spaces, 4 spaces or tabs), duplicate-key sorting is optional, and the whole parse runs in your browser: paste API responses from internal systems, config files with customer names, anything — because the text never leaves your machine.
How to use JSON Formatter
- Paste the JSON (or drop a .json file) into the input pane.
- Pick your indentation: 2 spaces for code review diffs, 4 for logs you reproduce by hand, tabs for your own editor settings.
- Press Format. Parse errors are reported with the exact position — character and line — not a bare "Unexpected token".
- Optionally sort object keys alphabetically to make diffs against yesterday's payload meaningful.
- Copy the result or download it as a .json file; Minify strips whitespace when you need the compact form.
Worked example: a 40,000-character API response
Your payment gateway returns webhooks as one minified line. Paste it, choose 2-space indentation, and you can see in seconds that the "amount" field arrives in paise while your code treats it as rupees — a bug that used to take a debugger session. Format it once, copy it into the ticket, and the next reader sees the same structure without opening a tool.
At a glance
| Input | Raw JSON text, or a .json file from disk |
|---|---|
| Output | Formatted or minified JSON, copyable or downloadable |
| Parse errors | Reported with line and character position |
| Key sorting | Optional A-Z sort of object keys |
| Where it runs | Entirely in your browser — works offline after first load |
Frequently asked questions
- What is JSON Formatter?
- Pretty-print or minify JSON with configurable indentation and sorting.
- Is JSON Formatter free to use?
- Yes — JSON Formatter is free to use, with no sign-up, no install and no account.
- Does JSON Formatter upload or store my data?
- No — JSON Formatter runs entirely in your browser, so your text, files and results never leave your device.
- Do I need to install anything to use JSON Formatter?
- No — it works in any modern browser (Chrome, Edge, Firefox, Safari) with no downloads, accounts or plugins.
- Does formatting change my data?
- Whitespace and key order in objects are the only things that can change — JSON objects are unordered by specification, so a pretty-printed file and the original parse to identical values. Array order, nulls, numbers and strings are preserved exactly; the formatter never coerces types.
- How large a file can it handle?
- Several megabytes of JSON format in well under a second on a laptop because the work is a single native JSON.parse in your browser's engine — there is no upload step and no server queue. Files built for ingestion pipelines (tens of MB) will feel slow on a phone, which is a device memory limit, not a tool limit.
- Is a formatted JSON still valid JSON?
- Yes. Formatting only inserts whitespace between tokens; pretty-printed JSON parses to exactly the same value as minified JSON, so you can round-trip between the two freely.