HMAC Generator - Free Online Tool | PivaBox

Generate HMAC signatures using SHA-1, SHA-256, SHA-384, SHA-512 with a secret key

How to Use HMAC Generator

1. Enter the message you want to sign and your secret key in the input fields
2. Select the hash algorithm (SHA-1, SHA-256, SHA-384, or SHA-512) and your key format (Text, Hex, or Base64)
3. Click Generate HMAC to compute the signature — use the copy button to save the result, or paste an expected value to verify

Frequently Asked Questions

Is HMAC Generator free?

Yes, PivaBox HMAC Generator is completely free. All computation runs locally in your browser using the Web Crypto API.

Are my messages or secret keys uploaded to a server?

No. All HMAC generation happens entirely in your browser using the <code>crypto.subtle</code> API. Your messages and secret keys never leave your device.

What is HMAC used for?

HMAC (Hash-based Message Authentication Code) is used to verify message integrity and authenticity. It combines a secret key with a hash function to produce a signature that proves the message came from someone who knows the key. Common uses include API authentication, JWT signing, webhook verification, and message integrity checks.