HMAC Generator
Calculate Hash-based Message Authentication Codes securely using secret keys.
Security
Client-side Encryption
Multiple Algorithms
HMAC Output
About HMAC
HMAC (Hash-based Message Authentication Code) involves a cryptographic hash function and a secret cryptographic key.
It verifies both the data integrity and the authentication of a message.
Commonly used in APIs (like AWS, Stripe) to sign requests and ensure they haven't been tampered with.
Algorithm Guide
- SHA-256: Standard for most modern applications. Secure and fast.
- SHA-512: More secure, slightly slower but better for 64-bit systems.
- SHA-1: Legacy. Use only if required for compatibility.
Frequently Asked Questions
Is the secret key safe?
Yes. The HMAC is calculated entirely in your browser using the Web Crypto API. Your secret key and message are never sent to any server.
What is the difference between Hash and HMAC?
A normal hash (like SHA-256) only proves data integrity. HMAC uses a secret key, so it proves that the sender also possesses the secret key (Authentication).