How to use this developer tool
- Paste the message to sign.
- Enter the secret key.
- Choose the HMAC algorithm.
- Select hex or base64 output.
- Copy the generated signature for testing.
#050 · Security Developer Tool
HMAC Generator
HMAC Generator signs a message with a secret key using common HMAC algorithms. It is useful for API authentication tests, webhook signature examples, request signing, and reproducible message authentication workflows.
Developer Input
Message and secret keyAd space
What this developer tool does
This tool creates a keyed message authentication code from a message and secret key using the selected SHA family hash.
Encode message and key → import key for HMAC → sign with selected SHA algorithm → convert signature to hex or base64 → display stats.
Keep real production secrets private. Use this browser-side tool for local testing and reproducible examples.
Example
Message GET /api/orders plus a secret key returns a deterministic HMAC signature for the selected algorithm.
Tips for better output
- Use HMAC-SHA256 for common API signature tests.
- Keep newline and timestamp formatting exactly the same as the server expects.
- Never paste production secrets into untrusted environments.
FAQ
how to generate hmac sha256 signature online
Enter the message, secret key, choose HMAC-SHA256, and generate the signature.
how to create hmac signature for api authentication
Build the exact message string required by the API and sign it with the shared secret.
how to output hmac as base64
Choose Base64 as the output format before generating the HMAC.
what is the difference between hash and hmac
A hash uses only the message, while HMAC uses a secret key plus the message.
how to test webhook hmac signature
Paste the webhook payload and signing secret, then compare the generated signature with the webhook header.
Related developer tools
HMAC options
| Algorithms | SHA1, SHA256, SHA384, SHA512 |
|---|---|
| Output | Hex or Base64 |
| Inputs | Message and secret key |
| Use case | API signatures |