Before you start
What you need
A test message, test secret, agreed SHA-2 algorithm, and output encoding.
Developer & Data
HMAC Generator
Create an HMAC test signature from a message and secret using browser Web Crypto.
- 01Runs in this browser
- 02Limits are explicit
- 03Copy or download output
No black box
How this tool handles the input
The secret is imported as a non-exportable in-memory HMAC key, then Web Crypto signs the UTF-8 message.
What you get
What the page gives back
An HMAC value for controlled interoperability testing.
Keep in mind
Use the result responsibly
Do not paste production signing secrets. HMAC verification also depends on exact bytes, canonicalization, timestamps, and replay policy.
Practical uses
Where this tool earns its place
- Check an integration test vector.
- Compare hexadecimal and Base64 signatures.
- Verify exact message-byte handling before server implementation.
Verified data boundary
Source text stays on this page.
The published contract marks these tools as client-only processing. Nirmion uses the API only to confirm that this workspace is enabled in MySQL; source values and results are not sent to Flask.