No. Formatting, validation and minification run in your browser. The page's security policy blocks network requests from the page, so your JSON is not sent anywhere.

JSON Formatter – Format & Validate JSON Locally

Q: Does this JSON formatter store my data?

No. There is no account, no history, no save or share feature and no server-side storage. When you close or reload the page, the text is gone.

Q: Can I format sensitive JSON?

The JSON stays in your browser and is never uploaded. As with any data, follow your organisation's rules for handling secrets on your device.

Q: How do I validate JSON?

Paste or load your JSON and press Validate. Invalid JSON is reported with the line, column and a readable reason, such as a trailing comma or an unquoted key.

Input JSON

Result

Ready. Nothing leaves this page.

🔒 Local only: this page has no server-side save or share feature, and its security policy blocks it from sending network requests.

Format and beautify JSON

Paste JSON or load a .json file, choose 2 spaces, 4 spaces or tabs, and press Format. The result keeps your data exactly as written - key order, duplicate keys, number spelling such as 12345678901234567890 or 1e400, and string escapes are not changed. Only whitespace is.

Validate JSON

Press Validate to check the syntax. Invalid JSON is reported with the line and column and a readable reason - for example a trailing comma, a missing comma, single quotes, an unquoted key or a comment.

Minify JSON

Minify removes all insignificant whitespace, producing the smallest equivalent JSON text without changing any value.

How privacy works here

Everything runs in your browser. There is no account, no history and no save or share link, so there is nothing stored on a server that could later be exposed. The page's Content Security Policy sets connect-src 'none', which blocks the page from making network requests at all. Like any website, the static host receives standard request information (such as IP address and browser) when the page itself is loaded - never the JSON you paste.

FAQ

Is my JSON uploaded?

No. Formatting, validation and minification run in your browser, and the page is blocked from sending network requests.

Does this JSON formatter store my data?

No. There is no account, history, save or share feature and no server-side storage. Reloading the page clears everything.

Can I format sensitive JSON?

Your JSON stays in your browser and is never uploaded. As with any secret, follow your own organisation's rules for handling it on your device.

How do I validate JSON?

Paste or load the JSON and press Validate. Errors show the line, the column and the likely cause.

What does an "unexpected" error mean?

The parser found something that is not allowed at that position - often a missing comma, a trailing comma before } or ], or text that is not in double quotes.

How large can the JSON be?

Files up to 10 MB are tested; larger inputs are processed off the main thread but are limited by your device's memory.