MACs 3 tools Browser only

Message Authentication Codes

Keyed hash functions for data integrity and authenticity verification. HMAC with multiple underlying hash algorithms and NIST-standard KMAC variants.

About MACs

MAC algorithms like HMAC and KMAC provide message authentication using secret keys, ensuring both data integrity and authenticity.

Runtime

All tools run locally in the browser using WebAssembly and JavaScript hash libraries.

KMA

KMAC128

Create KMAC128 authentication tags online - NIST SP 800-185 Keccak-based MAC with 128-bit security. Variable-length message authentication with customizable key and personalization strings.

KMA

KMAC256

Create KMAC256 authentication tags online - NIST SP 800-185 Keccak-based MAC with 256-bit security. High-assurance message authentication with variable-length output for critical applications.

HMA

HMAC

Create HMAC signatures online - standard message authentication code for API security and JWT tokens. Generate secure MACs with SHA-256, SHA-512, or any hash function for data integrity verification.

MACs FAQ

When should I use a MAC instead of a hash?

Use a MAC when you need a secret key to prove message authenticity as well as integrity. Plain hashes do not authenticate who created the data.

Should I choose HMAC or KMAC?

HMAC is the most broadly compatible choice. KMAC is appropriate when your system already uses SHA-3 or needs NIST SP 800-185 customization features.