What is JWT Generator — Create JSON Web Tokens?
The JWT Generator is a development tool that compiles JSON Web Tokens (JWT) by combining custom headers, payload claims, and sign secrets. You can define key parameters like client ID, roles, scope, and token expiry (`exp`). The tool computes the cryptographic signature using HMAC algorithms (HS256) entirely in your browser, generating a copyable token for testing.
How to Use JWT Generator — Create JSON Web Tokens
- Configure your claims in the Payload JSON editor (e.g., add `sub`, `name`, `roles`, or `exp`).
- Enter a secret signing key (passphrase) in the signature config box.
- Set the token lifetime or expiration duration.
- Click 'Generate JWT' to compile, sign, and display the encoded token on the screen.
Common Use Cases
- API developers testing authentication middleware by generating mock user tokens with specific permissions.
- Frontend developers simulating token authentication flows in local test sandboxes.
- Security engineers testing how systems handle expired tokens or invalid signatures by altering claims.
Pro Tips & Best Practices
- In production, never use HS256 (symmetric keys) for public APIs where clients need to verify tokens — use asymmetric algorithms like RS256 where only the auth server has the private key.
- Make sure the `exp` claim is in seconds (Unix epoch time), not milliseconds, as required by the JWT specification.