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JSON formatter & validator

Beautify, minify and validate JSON with precise error messages — paste it or drop a file, all on your device.

A .json file — or just paste below · validated on your device, nothing is uploaded

Valid JSON · object, 5 keys · 11 nodes

JSON in

Formatted out

Runs in your browser. Files are never uploaded — you can go offline after the page loads.

How to use the JSON Formatter

  1. Paste JSON or drop a .json file.
  2. Pick an indent (or minify), optionally sort keys — it validates live.
  3. Copy the result or download the .json file.

Easy to use

Drop files, pick options, download. Whole folders at once, no signup, no daily limit.

Best quality

The same engines the professionals use — SVGO, resvg, MozJPEG, libwebp, libavif — compiled to run in your browser.

Private & secure

Files are processed on your device and never uploaded. Close the tab and nothing remains anywhere.

Beautify, minify and validate — privately

Paste a messy API response or a hand-edited config and get it pretty-printed at 2, 4 or tab indent, or minified to a single line. Validation runs as you type: if something is off, you get the parser's message with the exact line and column, so you go straight to the stray comma. Optional recursive key sorting lines two files up in a diff so you see real changes, not reordering noise.

All of it happens in your browser — nothing is uploaded — which matters because JSON payloads often carry tokens, personal data or internal details you should not paste into a random website. For tabular data, the spreadsheet converters and CSV tools cover the CSV and Excel side.

Frequently asked questions

Is my JSON sent to a server?

No. Parsing, formatting and validation all happen in your browser, so API responses, config files and anything else you paste stay on your device — safe for sensitive payloads.

What does the validator tell me?

If the JSON is invalid it reports the parser’s message with the exact line and column of the problem, so you can jump straight to the stray comma or missing quote.

Why sort keys?

Sorting object keys alphabetically makes two JSON files line up in a diff, so you can see real changes instead of reordering noise. It is applied recursively and is optional.

Your files never leave your device

Most online converters upload your file to a server. InfyTool ships the actual encoders to your browser as WebAssembly instead, so processing happens inside your tab — faster for batches, and nothing to delete afterwards.

  • No upload, ever. Turn off Wi-Fi after the page loads and every tool keeps working.
  • No limits. No file-size cap, no queue, no watermark, no account.
  • Runs on your CPU. Batches use several cores in parallel; nothing is throttled.

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Need icons or SVGs to start from?

InfyTool is built by the same team as these free libraries.