HMAC Generator

Generate HMAC signatures (SHA-256/384/512) for API auth testing — all local.

Secret key: Message: Algorithm:

Signature (hex):

Signature appears here…

How to use

Enter a secret key and message, pick an algorithm, and click Sign. Everything runs in your browser.

What is HMAC used for?

Signing API requests and webhooks so the receiver can verify the sender knows the secret key.

Is my secret key safe?

Yes — the key never leaves your browser; signing uses the local Web Crypto API.

☕

Every tool runs 100% in your browser — no uploads, no signups. If a tool saved you time, consider supporting us with a small donation.