Is JWT Signer / Encoder free?

Yes, JWT Signer / Encoder is completely free to use with no signup required.

Does JWT Signer / Encoder send my data to a server?

No. JWT Signer / Encoder runs entirely in your browser using client-side JavaScript. Your data never leaves your device.

Build a JWT from header + payload and sign it with HS256/384/512 using WebCrypto. Your secret never leaves the browser.

DevTab

Never leaves your browser

Build and sign a JWT from a header, payload, and HMAC secret entirely client-side.

Algorithm

Header

Payload

Secret (HMAC key)

Signed JWT

Awaiting InputSigned entirely in-browser via WebCrypto — your secret never leaves this tab.