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JSON Formatter

Prettify, validate, minify and explore JSON as a tree.

Free, no uploads, no sign-up. Runs 100% in your browser.

How JSON Formatter works

JSON Formatter runs entirely in your browser. Prettify, validate, minify and explore JSON as a tree. Under the hood it uses Plain TypeScript (small, dependency-free code that runs instantly in your tab). Your files are read into this tab’s memory, processed on your own CPU, and handed back to you as a download. Nothing is sent to a server.

How to use JSON Formatter

1. Open JSON Formatter and paste or type your input.
2. Results update instantly as you type.
3. Tweak options such as format, indentation or algorithm.
4. Copy the output or download it as a file.

Tips

• Errors show the exact line and column.
• Switch to tree view to explore large payloads.

JSON Formatter FAQ

Are my files uploaded?

No. This tool runs entirely in your browser tab. Files are read from your disk into memory and the result is generated locally.

Is it free? Are there limits or watermarks?

Free and open source (MIT). There are no file-size caps, daily quotas, accounts or watermarks.

Does it work offline?

Yes, once the page (and any engine it needs) has loaded, it keeps working without a connection thanks to the service worker cache.

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