HMAC Generator & JWT Token Builder

Generate HMAC signatures using SHA-256, SHA-384, or SHA-512. Automatically builds JWT tokens from JSON payloads.

Secret Key

Payload / Message

Algorithm

Note: All HMAC and JWT generation happens entirely in your browser using the Web Crypto API. Your secret key never leaves your device.

For JWT generation, the payload must be valid JSON. The tool will automatically generate a JWT token with the standard header {"alg": "HS256", "typ": "JWT"}.

Frequently Asked Questions

Got questions? We've got answers. Search below or browse through our most commonly asked questions.

HMAC (Hash-based Message Authentication Code) is a specific type of message authentication code involving a cryptographic hash function and a secret cryptographic key.

No. The HMAC generation happens entirely client-side in your browser using the Web Crypto API.