JWT Generator
Build and sign a test JSON Web Token
typ and alg are set automatically from the algorithm above.
Generated Token
Enter a key/secret above to generate a token.
A JWT builder for generating test tokens — write header and payload claims, pick an algorithm, and sign with a secret (HMAC) or a private key (RSA/ECDSA), or build an unsigned token for negative testing. The companion to the JWT Debugger above, for when you need to create a token rather than inspect one.
- Is my secret or private key sent anywhere?
- No. The token is built and signed entirely in your browser using the Web Crypto API — your secret or private key is never sent to a server, the same as the JWT Debugger’s verification step.
- Which algorithms are supported?
- HS256/384/512 (signed with a shared secret), RS256/384/512 and ES256/384/512 (signed with a PEM-encoded PKCS8 private key), and an unsigned "none" option for testing that a server correctly rejects tokens with no signature.
- Can I verify the token I just generated?
- Yes — copy it into the JWT Debugger on this site (or paste the matching public key/secret there) to decode and verify it, confirming it round-trips correctly.
- What are the header and payload fields for?
- The payload box holds your claims (sub, role, exp, or anything custom). The header box is for extra header fields like "kid" — the standard "typ" and "alg" fields are set automatically from the algorithm you pick, so they can't drift out of sync.