Beautify, minify, and validate JSON instantly — with syntax highlighting and clear error messages. Everything runs in your browser.
Runs in your browser — nothing uploaded
Keys, strings, and numbers highlighted
Clear messages for invalid JSON
No registration required
Paste your JSON in the left box and click Beautify. It is instantly pretty-printed with your chosen indentation on the right, and validated for errors. Completely free.
If the JSON is invalid, a red message shows the parser error and, where possible, the position of the problem so you can fix it quickly.
Yes. Click Minify to strip all whitespace and produce the smallest valid JSON on a single line, ready to copy.
No. All formatting and validation happen entirely in your browser. Your data is never uploaded — guaranteed privacy.
You can pretty-print with 2 spaces, 4 spaces, or tabs, depending on your code style preference.
Yes, it handles large JSON well since everything runs locally. Extremely large inputs depend on your device's memory.