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Fix HMAC signature mismatch

HMAC verification fails when the computed hash doesn't match the provided signature. Often due to encoding or message format.

Common causes

  • Wrong encoding (hex vs base64).
  • Different message format (body vs payload).
  • Secret mismatch.

How to fix

  • Use the same encoding as the provider (hex/base64).
  • Hash the exact payload the provider uses.
  • Use HMAC Checker to verify.

Use our tool

Check HMAC