Tool Hub

HMAC Generator

Compute an HMAC digest (SHA-256/384/512) for a message and secret key (WebCrypto)

Compute an HMAC digest for a message and secret key using the browser's WebCrypto API. Nothing leaves your browser.

HMAC (hex)

How to use

  1. Enter the message you want to authenticate in the message field.
  2. Enter the secret key in the key field.
  3. Select the algorithm: SHA-256, SHA-384, or SHA-512.
  4. Copy the hexadecimal HMAC digest from the output.
  5. All computation runs in your browser via the WebCrypto API — nothing is stored or sent anywhere.

Examples

  • Message "GET /api/data" with key "mysecret" and SHA-256 produces a 64-character hex digest used to verify the request signature.
  • Changing a single character in the message or key produces a completely different digest, confirming tamper detection.

Verify outputs before using in production. No warranty — see Terms.