HMAC Generator
Sign a message with HMAC using a secret key.
Message
HMAC output
About the HMAC Generator
Generate an HMAC signature for a message using a secret key and your choice of SHA hash algorithm, computed with the Web Crypto API. Useful for verifying webhook payloads or API request signing.
Examples
Sign a message
message + keyOutput
hex/base64 HMAC signatureKeyboard shortcuts
- Copy the main outputCtrl / ⌘ + Shift + C
- Download the resultCtrl / ⌘ + S
- Share this toolCtrl / ⌘ + Shift + S
- Reset the inputsAlt + R
- Open the tool search paletteCtrl / ⌘ + K
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Frequently asked questions
Read more
- Understanding JWT: structure, claims and safe verification
What is actually inside a JSON Web Token, which claims matter, and why decoding a JWT is not the same as verifying it.
- Choosing a hashing algorithm: MD5 vs SHA-1 vs SHA-256 vs bcrypt
Checksums, digital fingerprints and password storage all use 'hashing' — but the right algorithm depends entirely on the job.
- Choosing a hashing algorithm: MD5 vs SHA-256 vs bcrypt vs Argon2
Cryptographic hashing and password hashing solve different problems. Here's when to use each algorithm and why the wrong choice is a security bug.
Version 1.0.0 · Updated 2026-08-06 · Runs entirely in your browser