Security utility
HMAC Generator
Create an HMAC-SHA-256 or HMAC-SHA-512 message authentication code.
● This tool runs entirely in your browser. Your input is never uploaded to our servers.
Output
Your result will appear here…
How to use HMAC Generator
- Enter the message and secret key.
- Choose HMAC-SHA-256 or HMAC-SHA-512.
- Select Generate HMAC and compare using the same key and algorithm.
Example
Input:
timestamp=1735689600&event=created
Output:
HMAC-SHA-256: computed digest
Use cases
- Test webhook signature implementations.
- Create local API signing examples.
- Compare HMAC outputs for a known test vector.
About this tool
Create an HMAC-SHA-256 or HMAC-SHA-512 message authentication code. Processing happens locally in your browser, so your input is not sent to a server or included in analytics.
Frequently asked questions
Is HMAC the same as a plain hash?
No. HMAC combines a secret key with a hash function to authenticate a message.
Is my secret key transmitted?
No. Web Crypto uses the key locally in your browser.
Can I share the generated output?
The HMAC alone does not reveal the key, but treat signing workflows and associated messages according to your security policy.