JWT Encoder
Signed locally in your browser with crypto.subtle HMAC and Base64URL encoding. Your payload and secret stay only on this page.
Sign a verifiable JWT
Enter a header, payload, and secret to produce a real, signed JSON Web Token using HMAC (HS256, HS384, or HS512). The header alg is forced to match the selected algorithm. The result verifies against the JWT Decoder and jwt.io, and the secret never leaves the page.