No. It is parsed entirely in your browser, so your data — including any tokens or secrets — never leaves your device.

Does it validate JSON?

Yes. If the JSON is invalid, it shows the parser error so you can find the problem; if valid, it formats or minifies it.

JSON Formatter & Validator — Beautify / Minify Free

JSON Formatter & Validator

Beautify, validate and minify JSON instantly — with clear error messages, and100% in your browser. Safe for API tokens and config files.

JSON input

Output

🔒 100% private — your JSON is parsed in your browser, never uploaded. Safe for tokens & configs.

What it does

Format / Beautify — turns minified or messy JSON into clean, indented, readable JSON.
Validate — if the JSON is broken, you get the exact parser error to fix it.
Minify — strips whitespace to make JSON as small as possible for production.

Why a private, in-browser formatter?

JSON often contains sensitive data — API responses, tokens, credentials, config. Many online formatters upload what you paste. ToolFern parses everything locally in your browser, so your data never leaves your device.

Frequently asked questions

Is my JSON sent anywhere?

No — it’s parsed in your browser and never uploaded.

Will it tell me what’s wrong?

Yes — invalid JSON shows the parser’s error message.

Related: Base64 encode/decode