Generate Secure HMAC Authentication Codes
Compute cryptographically verified HMAC codes using SHA-256, SHA-512, SHA-384, or SHA-1 with secret signing keys.
About This Tool
HMAC Generator & Verifier calculates Hash-based Message Authentication Codes used for API request signing, webhook authentication (GitHub, Stripe, Shopify), and tamper-proof message verification.
Key Features
How to Use
- 1Enter the message or webhook payload in the input field.
- 2Provide your secret API key or signing secret.
- 3Select your hashing algorithm (HMAC-SHA256, HMAC-SHA512) and output encoding (Hex or Base64).
- 4Click 'Generate HMAC Code' and copy the resulting signature.
Why Use ToolSnippet HMAC Generator & Verifier?
Tips for Best Results
- Use HMAC-SHA256 for standard modern webhook verification (GitHub, Stripe, AWS)
- Always keep your secret key confidential
Frequently Asked Questions
What is an HMAC?
HMAC stands for Hash-based Message Authentication Code. It is a cryptographic mechanism that combines a secret key with a message to verify both data integrity and authentication.
Is my secret key sent to any server?
No. The entire HMAC signature is calculated locally in your browser using window.crypto.subtle.
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