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TOOL · 29 · Data & Utility

JSON Formatter & Validator

Pretty-print or minify JSON, validate syntax with clear error location, and copy or download.

In short
JSON Formatter & Validator pretty-prints or minifies any JSON snippet, points to the exact line and column of syntax errors, and lets you copy or download the result. Runs entirely in your browser.

Drop files here or click to browse

Or upload a .json file

How it works

  1. Step · 01

    Paste JSON into the input, or drop a .json file.

  2. Step · 02

    Pick pretty-print (with your indent size) or minify.

  3. Step · 03

    Copy the result to your clipboard, or download it as a .json file.

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Frequently asked questions

What does the error message tell me?
If your JSON is invalid, the tool reports the line and column of the first parse error along with the underlying reason (missing comma, unexpected token, unterminated string, etc.).
How large a JSON file can I paste?
There is no hard cap — parsing runs locally in your browser. Files in the tens of megabytes work on a normal laptop; extremely large payloads may slow the textarea.
Are my files uploaded to a server?
No. Files are processed directly in your browser using JavaScript and WebAssembly. Nothing is uploaded to our servers, so your documents never leave your device.
Does it work on mobile?
Yes. The tools run in any modern browser on desktop, tablet, or mobile (Chrome, Edge, Safari, Firefox). Very large files may be slower on low-end phones.