HMAC Generator
Generate HMAC signatures using SHA-256, SHA-384, or SHA-512. Client-side only.
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What is this tool?
HMAC (Hash-based Message Authentication Code) generator creates cryptographic message authentication codes using a secret key and hash function. HMAC ensures both data integrity and authenticity, verifying that a message was not tampered with and was sent by someone with the correct key. Supports MD5, SHA-1, SHA-256, SHA-512 hash algorithms.
How to use
- 1
Enter message
Type the data to authenticate.
- 2
Enter secret key
Type or paste the secret key used for HMAC calculation.
- 3
Select algorithm
Choose hash algorithm (SHA-256 recommended).
- 4
Get HMAC
View the HMAC in hex or base64 format.
Frequently Asked Questions
What is HMAC used for?
HMAC is used for API authentication (OAuth, JWT signing), message integrity verification, password verification, and preventing tampering in communications. Unlike plain hash, HMAC uses a secret key so only parties with the key can generate or verify the code. SHA-256 HMAC is the most commonly used variant.
HMAC vs regular hash?
HMAC uses a secret key for authentication.
What encryption standard is used?
The tool implements standard algorithms as defined by NIST. For production security use well-tested libraries.