JSON formatter & validator

Beautify messy JSON with custom indentation, minify it for production, and validate syntax instantly — all locally in your browser, nothing uploaded.

How to JSON formatter & validator

1. Step 1. Paste or type your JSON into the input buffer.
2. Step 2. Pick an action: beautify (choose indentation), minify, or validate.
3. Step 3. Copy the formatted result from the output buffer.

Frequently asked questions

Is my JSON data sent to a server?

No. Formatting and validation run entirely in your browser with JavaScript — the data never leaves your machine.

What JSON errors can it detect?

Syntax errors such as trailing commas, unquoted keys, single quotes, and truncated structures, with the parser message shown in the error strip.

Can it handle large JSON files?

Yes — parsing runs locally, so speed depends on your device rather than an upload limit.