Privacy & Security · Free Tool

HMAC Generator

Compute an HMAC signature from a message and a secret key using the browser’s native Web Crypto — SHA-256, 384, 512 or 1, in hex or Base64. The key and message never leave your device.

Message

Secret key

Hash

Output

HMAC

How it works

An HMAC (hash-based message authentication code) proves a message hasn’t been tampered with by anyone who doesn’t hold the shared secret key. This tool uses the browser’s native Web Crypto SubtleCrypto.sign — the key and message never leave your device. The same key + message + hash always produce the same code, so you can verify signatures from other systems.