HMAC Generator
Create keyed HMAC-SHA signatures from a message and secret key locally.
Keyed HMAC signatures
An HMAC proves a message was created by someone holding a shared secret, which is how webhooks and API requests are verified. This generator computes HMAC-SHA signatures from a message and key using the browser’s Web Crypto, so you can reproduce or check a signature.
Because it uses SubtleCrypto, the signing is real and standards-based. It is handy for debugging webhook verification and understanding how a provider signs requests — though for genuine production secrets, be mindful of where you paste them.
Private and instant
Everything runs locally in your browser using standard web APIs — nothing is uploaded, logged, or stored on any server — so the tool works offline, responds instantly, and keeps whatever you paste in on your own device. That makes it safe to use even for confidential, client, or internal data you would never send to an unknown website.
Frequently Asked Questions
What does the hmac generator do?
It processes pasted developer text in your browser and writes a usable result to the output panel.
Does this send code or data to a server?
No. The tool runs client-side in your browser and does not upload your input.
What are the limits?
It is designed for everyday snippets, configuration values, and small files rather than huge production datasets.
Is this free?
Yes. It is a free browser utility with no account required.
Practical utilities for everyday web development work.