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Security & Identity

HMAC Generator / Verifier

Generate or compare an HMAC using an exact message and shared test secret.

Calculations run in your browser. The tool does not send your inputs to a server.

01Your inputs

Local workspace

Start with the sample below, or enter your own values.

The sample is editable. Keep the input format consistent with the action you choose.
Use a synthetic example on shared devices. This value is processed in this browser.

02Your result

Your result will appear here. Choose an action after checking your inputs.

A quick guide

How to use this tool

  1. Check the example and the unit beside each input.
  2. Enter your values and choose Generate or Verify.
  3. Review the result and assumptions, then copy what you need.

Reset example restores the starting values. Clear removes text and number inputs, returns choices to their first valid option, and removes the result.

Reference guide

Explanation and worked examples

Verify expects a hexadecimal signature. A match confirms the supplied values agree; replay prevention and sender trust require additional controls.

Use in day-to-day IT work

Inspect a test token, certificate or integrity check while diagnosing an authentication issue.

Checks before applying the result

  • Use synthetic examples on shared devices and review copied or downloaded output before sharing it.
  • Use the production platform or a maintained verification library for trust, permissions, expiry and revocation decisions.
New to the terminology?
JWT
JSON Web Token: encoded claims that require verification before trust.
HMAC
A keyed message authentication code for checking integrity.
Fingerprint
A digest used to identify exact certificate bytes.

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