HMAC Generator
Free online tool · runs in your browser
Generate HMAC signatures locally.
Quick tutorial
- 1Enter message and secret key.
- 2Select algorithm.
- 3Click Generate.
Free online hmac generator
Generate HMAC signatures locally with Web Crypto. Enter a message and secret, choose the algorithm, and copy the hex digest. The secret exists only in memory during generation — it is not stored. Never paste production API secrets on a shared computer.
How to use HMAC Generator
- Enter message and secret key.
- Select algorithm.
- Click Generate.
Limitations
- Never paste production secrets on public/shared machines.
Example
Input
message + secret
Output
HMAC hex digest
FAQ
Frequently Asked Questions
Where is my HMAC secret stored?
Nowhere. It lives in memory only while you generate the signature.
What is HMAC used for?
Message authentication — proving a payload was signed with a shared secret (for example webhook signatures).
Where is the secret stored?
Nowhere. It exists only in memory during generation.
Is HMAC Generator free to use?
Yes. HMAC Generator on ShadowReference is free, with no account, no watermarks, and no server-side processing.
Does this tool send my data to a server?
No. All processing happens locally in your browser. Your input never leaves your device.