Test a webhook signature
Create an HMAC from a test secret and request body, then compare it with the server implementation.
HMAC Message Authentication Code Generator
HMAC Message Authentication Code Generator
Calculate a SHA-family HMAC from a message and secret key, then view the result as Hex or Base64.
Key features
- Selects HMAC-SHA-1, SHA-256, SHA-384, or SHA-512.
- Processes the message and secret key as UTF-8 bytes.
- Switches the same authentication code between hexadecimal and Base64 output.
How to use
- Enter the message and secret key.
- Choose the hash algorithm.
- Copy the Hex or Base64 HMAC.
Examples
Check an API authentication example
Generate SHA-256, SHA-384, or SHA-512 HMAC output as Hex or Base64.
Privacy
The message, secret key, and HMAC calculation are handled by the browser's Web Crypto API.
Requirements
A modern browser with Web Crypto is required; this tool generates HMAC values but does not verify them.
Common questions
- How is HMAC different from a plain SHA hash?
- HMAC uses a secret key as well as the message. The same message produces a different authentication code with a different key.
- Can this tool verify the generated HMAC?
- There is no separate verification action. Recreate the value with the same algorithm, key, and message, then compare it with the expected value.
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