JSON Formatter & Validator

About this JSON formatter

This tool pretty-prints JSON with your chosen indentation, validates syntax with exact line and column error reporting, and can minify JSON to a single compact line. It handles large documents and never sends your data anywhere — parsing happens locally with your browser's native JSON engine, the same one used by Chrome and Firefox developer tools.

Frequently asked questions

Is it safe to paste sensitive JSON here?

Yes. The formatter runs 100% client-side in JavaScript. Your JSON never leaves your device and is not stored, logged, or transmitted.

Why does my JSON fail to validate?

The most common causes are trailing commas, single quotes instead of double quotes, unquoted keys, and comments — none of which are allowed in strict JSON. The error message shows the exact line and column of the first problem.

What does "minify" do?

Minifying removes all whitespace and newlines, producing the smallest valid representation of your JSON — useful for embedding in config files, HTTP requests, or environment variables.