HMAC

HMAC Generator

Generate HMAC-SHA1, SHA256, SHA512 online

πŸ”’ 100% client-side β€” your data never leaves this page
Input
πŸ”’ 100% client-side Β· Web Crypto API
Output
Enter a message and secret key to generate HMAC

About this tool

Generate HMAC (Hash-based Message Authentication Code) values instantly in your browser. Supports HMAC-SHA1, HMAC-SHA256, and HMAC-SHA512 algorithms. Enter your message and secret key to compute secure authentication hashes using the Web Crypto API. No data is transmitted β€” everything runs 100% client-side.

Frequently Asked Questions

What is HMAC?

HMAC (Hash-based Message Authentication Code) is a mechanism for verifying both data integrity and authenticity using a secret key combined with a cryptographic hash function.

What is the difference between SHA-1, SHA-256, and SHA-512?

They differ in hash length and security strength. SHA-256 and SHA-512 are more secure and recommended for modern applications, while SHA-1 is considered deprecated for high-security use cases.

Is my secret key safe?

Yes. All HMAC calculations are performed locally in your browser using the Web Crypto API. Your message and secret key are never transmitted to any server.