You are responsible for key management and output validation.
HMAC Calculator
Calculate HMAC signatures using SHA-256, SHA-1, or MD5 entirely in your browser. Zero-knowledge architecture, no key transmission.
Hash Algorithm
Key processed in your browser only.
Output Format
API Authentication
Use HMAC-SHA256 for API request signing. Include timestamp to prevent replay attacks.
Frequently Asked Questions
What is HMAC used for?
HMAC verifies message authenticity and integrity using a shared secret. It is common for API request signing and webhook payload validation.
Which algorithms are available?
SHA-256 (recommended), SHA-1, and MD5.
Is my secret key sent anywhere?
No. The key and message are processed locally in your browser and never leave your device.
Related Tools
Your inputs remain on your device.