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HMAC Signature Generator

Create HMAC-SHA256/SHA-1/SHA-512 signatures in hex or Base64, e.g. for webhook and API testing.

Tool inputs stay in your browser · optional AI search sends your query

Good to know: Uses the browser’s Web Crypto API. The secret never leaves your device.

How to use it (step by step)

  1. 1Type or paste your text into the “Message” box. There is already an example in it so you can see how it works; press Clear to start with your own.
  2. 2Choose your settings: “Secret key”, “Algorithm”, “Output”.
  3. 3The answer appears right away in the “Signature” box. No button needed.
  4. 4Press Copy and paste the result wherever you need it.

Words to know

Webhook
An automatic message one system sends another when something happens, like a text alert “payment received”.
HMAC / signature
A secret code made from the message and a secret key. If the code matches, you know the message is real and was not changed.
Hash / fingerprint (SHA-256)
A short code calculated from a file or text. Change even one letter and the code becomes completely different, so it proves nothing was altered.
Base64
A way to turn any file or text into plain letters and numbers so it can be sent safely inside text.
Hex / binary
Other ways of writing numbers. Binary uses only 0 and 1; hex uses 0–9 and A–F.
cURL / API request
cURL sends a request to a web address from the command line. APIs are web addresses that return data for programs.

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