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JSON formatter & validator — offline

Pretty-print, minify, and validate JSON without your data ever leaving the browser. Error positions included.

100% private — files never leave your device
Input
Output

How it works

  1. 1

    Paste JSON (or drop a .json file) into the input.

  2. 2

    Pick an indent style, optionally sort keys.

  3. 3

    Format or minify — then copy the result.

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Frequently asked questions

Is my JSON sent to a server to be formatted?

No. Parsing and formatting use your browser's built-in JSON engine — the data never leaves this page. API responses with tokens or customer data stay on your machine.

What does the validator report?

Whether the input is valid JSON, and for many syntax errors the exact line and column, so you can jump straight to the problem.

Can it sort object keys?

Yes — enable "Sort keys" to sort all object keys alphabetically at every depth, which makes diffs between two JSON documents much easier to read.