HMAC Generator
Generate HMAC signatures using a secret key.
💡 About HMAC
- HMAC: Hash-based Message Authentication Code
- Used to verify both data integrity and authenticity
- Common in API authentication (e.g., AWS, webhooks)
- Both sender and receiver must have the same secret key
- Stronger than simple hashing - includes secret key
About HMAC Generator
HMAC Generator computes a Hash-based Message Authentication Code by combining a message with a secret key using SHA-256, SHA-512, or other hash functions. HMAC is used to verify both the integrity and the authenticity of a message — common applications include signing webhook payloads, generating API request signatures, and validating JWT tokens with symmetric keys.
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Frequently Asked Questions
Is HMAC Generator free?
Yes, completely free. No signup, no account, no usage limits. Use it as much as you need.
Is my data secure?
All processing happens directly in your browser using JavaScript. Your data is never sent to any server, stored, or shared. It stays entirely on your device.
What is the difference between a hash and an HMAC?
A plain hash has no secret — anyone can compute it. An HMAC requires the secret key, so only parties with the key can produce or verify the signature.
Which algorithm should I use — HMAC-SHA256 or HMAC-SHA512?
HMAC-SHA256 is the most widely adopted choice and is secure for the vast majority of use cases. HMAC-SHA512 offers a larger output but provides no practical security advantage for most applications.