HMAC generator

Compute HMAC using Web Crypto (SubtleCrypto). Your secret and message stay in the browser.

Try it with this example

Choose SHA-256, SHA-384, or SHA-512, enter secret and message, then copy hex or Base64 output.

What is this tool?

How do I compute HMAC-SHA for an API? Enter a secret and message to get HMAC digests (hex and Base64). Uses Web Crypto in your browser—nothing is uploaded.