HMAC Generator
Create a keyed message code.
Runs in your browser. Nothing is uploaded — your input is processed on this device and discarded when you close the tab.
HMAC Generator
How to use this tool
- Enter your values in the fields above.
- Press Generate to see the result.
- Use Load sample to try the worked example, Copy result to copy it, or Clear to start again.
Worked example
With key “key” and the sample fox message, HMAC-SHA-256 gives f7bc83f430538424b13298e6aa6fb143ef4d59a14946175997479dbc2d1a3cd8. The same inputs always give the same code.
What this tool does not do / Limits
This computes a code from the key and message you enter. It does not sign requests for any real service, and a key typed here must never be a real production secret.
Frequently asked questions
Is my key sent anywhere?
No. The key and message are processed locally in your browser and are never uploaded anywhere.
Why does the browser version differ from the test version?
The browser prefers built-in Web Crypto when available and falls back to a built-in pure implementation otherwise. Both give the same result for the same inputs.
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