Generator
Generate or compare HMAC signatures from a payload and secret key, with algorithm and encoding controls that match the way real API and webhook integrations are usually debugged.
Best use case
This works best for webhook verification, API signature debugging, and checking whether key encoding or output encoding is the reason two HMAC values do not match.
Mode and sample
Better HMAC tools keep generation and verification close together because signature debugging usually needs both.
Signing inputs
HMAC mismatches often come from payload bytes, secret encoding, or output encoding, so those controls should be explicit.
Computed signature
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How to Use This HMAC Generator
Paste the exact payload, enter the shared secret, align the algorithm and encodings with your integration, then copy or compare the resulting signature.
Paste the exact payload you need to sign
Use the raw message body or string exactly as the receiving system expects it, including spacing and line breaks when they matter.
Enter the shared secret and choose key encoding
Pick UTF-8, hex, or Base64 depending on how the secret was originally given to your app or webhook consumer.
Set the algorithm and output encoding
Match the HMAC algorithm and signature format used by the integration so your generated value can actually be compared.
Copy or verify the resulting signature
Use the computed value directly or compare it against an incoming signature when you are debugging a mismatch.
When This Tool Is Most Useful
It helps most when a signature mismatch is blocking an integration and you need to isolate whether the problem is the payload, secret, algorithm, or encoding.
Webhook verification
Compare local signatures against incoming webhook headers when services like Stripe, Shopify, or custom systems report verification failures.
API request signing
Check whether your app is building the right HMAC signature before you ship or debug a rejected request.
Encoding mismatch debugging
Find out whether the issue is the secret format, message bytes, or output encoding instead of guessing blindly.
Security workflow testing
Generate known-good HMAC values during local testing so backend and client teams can align on expected output.
FAQs
What does this tool actually generate?+
It generates an HMAC signature from a payload, a shared secret key, and the selected hash algorithm.Why is key encoding important?+
Because the same-looking secret can produce a different signature depending on whether it is treated as plain text, hex bytes, or Base64 bytes.What is this most useful for?+
It is most useful for webhook verification, API signing checks, and debugging HMAC mismatches during integration work.Does this encrypt the message?+
No. HMAC proves message authenticity and integrity, but it does not encrypt or hide the message contents.