FAHAQ

HMAC Generator

Generate an HMAC signature with a secret key.

HMAC-SHA-256
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Signed locally via crypto.subtle.sign — your message and key never leave your device.

Free HMAC generator. Sign a message with a secret key using HMAC-SHA256, SHA384 or SHA512 via the Web Crypto API. Great for verifying webhooks and API requests. Runs locally in your browser.

How to use the HMAC Generator

  1. 01Choose a hash algorithm (SHA-256, SHA-384 or SHA-512).
  2. 02Enter your message and secret key.
  3. 03The HMAC hex signature is computed instantly — copy it.

Frequently asked questions

What is an HMAC?

HMAC (Hash-based Message Authentication Code) combines a secret key with a hash function to verify both the integrity and authenticity of a message. It's widely used to sign API requests and webhooks.

Is my secret key safe here?

Yes. The key and message are used only in your browser via crypto.subtle.sign and are never transmitted or stored. Still, avoid pasting production secrets on shared machines.