Generate Your HMAC Now
Create a keyed-hash message authentication code (HMAC) using SHA-256, SHA-1, or MD5. All processing is done in your browser.
What is an HMAC?
An HMAC (Keyed-Hash Message Authentication Code) is a type of hash that uses a secret key in addition to the message data. The result is a hash that proves both the integrity of the message (it hasn't changed) and its authenticity (it must have come from someone who knows the secret key).
Unlike a standard hash, two people will get different HMACs for the same message if they use different secret keys.
How Does the HMAC Generator Work?
This tool uses the `CryptoJS` library to perform the selected HMAC algorithm (e.g., HMAC-SHA256). It combines your message and your secret key, then hashes them together according to the HMAC standard. This process is one-way and happens entirely in your browser.
Use Cases for HMAC
- API Authentication: Securing API endpoints by requiring a valid HMAC signature with each request.
- Webhook Verification: Ensuring that a webhook POST request actually came from the service (like GitHub or Stripe) that claims to have sent it.
- JSON Web Tokens (JWT): The signature part of a JWT is often an HMAC.
Why Use Utils Hub's HMAC Generator?
- Instant and Free: Generate unlimited HMACs without cost.
- Private: Your message and secret key are never sent to our servers.
- Standard-Compliant: Uses trusted algorithms (SHA-256, SHA-1, MD5) via CryptoJS.
Frequently Asked Questions (FAQ)
What's the difference between Hash and HMAC?
A Hash (like SHA-256) proves data *integrity* (it hasn't changed). An HMAC proves *integrity* AND *authenticity* (it hasn't changed AND it came from a trusted source who has the key). HMAC is a hash *with* a secret key.
Which algorithm should I use?
HMAC-SHA256 is the modern, secure standard. HMAC-SHA1 is still common but is being phased out. HMAC-MD5 is considered insecure and should only be used for legacy systems.
Related Tools on Utils Hub
- Hash Generator – Simple, un-keyed hashing.
- AES Encryption/Decryption – Two-way encryption with a key.
- JWT Decoder – Decode and inspect JSON Web Tokens.