SIGN
JWT Signer (HS256 / HS384 / HS512)
Sign JWTs with a shared secret in your browser. Build header+payload, pick algorithm, get a signed token.
Runs entirely in your browser · Your input is never transmitted
PAYLOAD (JSON)
0 BReady
TOKEN
Ready —
How to use
- Paste or edit the payload JSON.
- Enter your HMAC secret.
- Pick algorithm. Copy the token.
Frequently asked
Why only HMAC algorithms?
Browser-side RSA/ECDSA signing requires importing a private key — possible but dangerous in a public tool. HMAC is safe because the secret never leaves your browser.