JWT Encoder
Sign JWTs via Python PyJWT on the server.
Payload (JSON)
Secret Key
Algorithm
Generated Token
Create signed JWTs online — HS256, HS384, HS512
Build and sign JSON Web Tokens locally in your browser with HMAC algorithms (HS256, HS384, HS512). Set custom claims and secrets to produce test tokens for development — your secret never leaves your machine.
Frequently Asked Questions
- Is it safe to enter my signing secret here?
- The token is signed entirely in your browser using the jose library — no network request is made. For production secrets, generating test tokens with a test secret is still the best practice.
- What is the difference between HS256 and RS256?
- HS256 uses one shared secret for both signing and verification; RS256 uses a private key to sign and a public key to verify. Use RS256 when verifiers should not be able to mint tokens.
- Which claims should a JWT contain?
- Standard claims include iss (issuer), sub (subject), aud (audience), exp (expiry), and iat (issued at). Keep payloads small — JWTs travel with every request.
- How do I verify the token I created?
- Paste it into our JWT Decoder to inspect the header and payload, or verify the signature in your application with the same secret and algorithm.