HMAC Generator

Overview

• Generates an HMAC (Hash-based Message Authentication Code) from a Message and a Secret.

• HMAC is used to verify that a message has not been tampered with and that the sender actually knows the shared secret.

• Supports three hash algorithms: SHA-256, SHA-384, and SHA-512.

Usage

1. 1

   Enter the Message (the string to hash) into the text area.

2. 2

   Choose a Secret and an algorithm (SHA-256 / SHA-384 / SHA-512).

3. 3

   Click the "Generate" button to display the HMAC value in hexadecimal. Use the "Copy" button to copy it to the clipboard.

Example

Message: hello world
Secret: my-secret
Algorithm: SHA-256

0aa5cf706962558525d3922c8b57ff2ec36ba9ee5f6ba7fdc6a5b6fda05df97

Use Cases

• Computing the expected HMAC value locally to check against it while implementing webhook or API request signature verification

• Confirming that a webhook signature received from an external service (such as a payment provider) is correctly computed from the shared secret

• Preparing test cases and test data for HMAC-based signature verification

FAQ

Notes

• Only HMAC-SHA256/384/512 are generated. HMAC-MD5 and HMAC-SHA1 are not supported.

• Do not enter a secret key that is actually used in production here.

• The generated result exists only on the page and is lost on reload, so copy and save it if you need to keep it.