🍋 Privacy & Security
HMAC Generator
Generate keyed-hash message authentication codes
chars
words
sentences
lines
HMAC Options
Results
Result
About HMAC Generator
Compute HMAC (Hash-based Message Authentication Code) using a secret key. Supports SHA-256 and SHA-512 algorithms.
How It Works
Uses Web Crypto API to import your secret key, then computes HMAC using crypto.subtle.sign(). The result proves both data integrity and authenticity — only someone with the key can produce the same HMAC.
Step by Step
- 1 Enter the message to authenticate
- 2 Enter your secret key in the second input
- 3 Select HMAC algorithm (SHA-256 or SHA-512)
- 4 Click Generate to compute the HMAC
- 5 Copy the HMAC value
Tips
- Use a strong, random secret key (at least 32 characters)
- HMAC is used in API authentication, JWT signing, and webhook verification
- Unlike plain hashing, HMAC requires a secret key to verify
- SHA-256 HMAC is the standard for most API integrations
Frequently Asked Questions
What is the difference between a hash and HMAC?
A hash only proves integrity (data has not changed). HMAC proves both integrity AND authenticity (data came from someone with the secret key).
Where is HMAC used?
API authentication (AWS Signature V4), webhook verification (Stripe, GitHub), JWT signing (HS256), and message authentication in protocols like TLS.