Generate HMAC signatures online using a message and secret key. Create SHA-1, SHA-256, SHA-384, and SHA-512 HMAC hashes in hex or base64 format.
Useful for API authentication, webhook verification, signed requests, backend testing, and security learning.
Enter your message, add a secret key, choose an algorithm, and generate a clean HMAC signature instantly.
| Field | Value | Meaning |
|---|---|---|
| Generate HMAC to see output details. | ||
An HMAC Generator helps create message signatures for APIs, webhooks, authentication, and secure request validation.
Generate HMAC signatures from a message and secret key using SHA-1, SHA-256, SHA-384, or SHA-512.
Convert the HMAC result into hex, base64, or both formats for API headers and verification.
Use the generated signature for signed requests, webhook checks, and development testing workflows.
HMAC stands for Hash-based Message Authentication Code. It combines a secret key with a message and a hash algorithm to create a signature. The receiver can use the same secret key to confirm that the message was not changed.
HMAC is commonly used in API authentication, webhook signature verification, signed URLs, request validation, payment callbacks, and backend-to-backend communication.
| Algorithm | Common Use | Output Strength |
|---|---|---|
| HMAC SHA-1 | Legacy systems | Older, less recommended |
| HMAC SHA-256 | Modern API signing | Strong and widely used |
| HMAC SHA-384 | Higher security needs | Stronger output length |
| HMAC SHA-512 | Large security-sensitive systems | Longest output |
Generate an HMAC signature in three simple steps.
Paste the text, JSON payload, webhook body, API path, or request string that needs a signature.
Enter the shared secret key and select the HMAC algorithm and output format.
Generate the HMAC signature, copy it, download the report, or copy an example signature header.
Common questions about HMAC signatures, secret keys, algorithms, APIs, and security.