Free · Sign a token with a shared secret

JWT HS256 Signer

Turn JSON claims into a signed HS256 token with a secret that stays in this tab.

Real jose checks
Private in your browser
Copy or download the result

Sign JWT

The input and result stay in this browser tab.

1Add the input

Claims JSONOne JSON object, up to 96 KB.Shared secret

At least 32 UTF-8 bytes for HS256.

2Check the result

Your checked result will appear hereTry the safe sample if you do not have test data.

Private by design. Keys, secrets, claims, and messages never leave this tab. Do not paste a production private key on a shared device.

Three simple steps

How to use it

Edit the sample claims.
Enter a long test secret.
Sign and copy the token.

Your keys stay on this device

jose and Web Crypto do the work inside this browser tab. Bookify does not upload or save keys, secrets, tokens, or messages. A valid signature proves the input matches the key, but you must still trust where that key came from.