🔒 Security Note: Data is processed locally in your browser and is not uploaded.
All computations happen locally for privacy and speed.
Choose from popular SHA variants to match your spec.
See HMAC output immediately as you type or paste input.
Copy results in uppercase or lowercase for compatibility.
Generate HMAC signatures for authenticated API calls.
Validate webhook payloads by matching signature headers.
Check HMAC outputs across environments for consistency.
Confirm secret keys and payload formats during setup.
Paste the message you want to sign.
Use the shared secret for authentication.
Select the hash algorithm your API requires.
Copy the output and use it for signing.