Generate JSON Web Tokens with custom header, payload, and secret key.
Demo Tool Warning
This is a simplified JWT generator for educational purposes. For production use, implement proper HMAC-SHA256 signing using a crypto library like jsonwebtoken or jose. Never store secrets in client-side code.
About JWT
Common Claims
iss - Issuer
sub - Subject
aud - Audience
exp - Expiration Time
nbf - Not Before
iat - Issued At
jti - JWT ID
Algorithms
HS256 - HMAC SHA-256 (symmetric)
RS256 - RSA SHA-256 (asymmetric)
ES256 - ECDSA SHA-256 (asymmetric)
PS256 - RSA-PSS SHA-256
Production Best Practices
✓ Use strong secret keys (at least 256 bits)
✓ Always set expiration time (exp claim)
✓ Store secrets securely (environment variables, not in code)
✓ Use HTTPS for token transmission
✓ Implement token refresh mechanism
✓ Validate tokens on every request
✓ Use libraries like jsonwebtoken (Node.js) or jose (browser)