catalyst.tools
100% free
No login

HMAC Generator

Hash & Security

Compute HMAC-SHA256 and HMAC-SHA512 message authentication codes for API signing.

#hmac#hmac sha256#api signing#webhook signature

About HMAC Generator

Compute HMAC-SHA256 and HMAC-SHA512 message authentication codes for API signing. HMAC Generator runs entirely in your browser — no installation, no uploads, and no data ever leaves your device.

Common use cases: sign api webhook payloads for verification; implement request authentication for rest apis; validate message integrity in secure communications. Whether you are debugging, prototyping, or building production code, having a fast and private tool for this task saves time compared to writing one-off scripts or using an online tool that logs your data.

Like every tool in Catalyst, this one is free forever, requires no login, and is safe to use with confidential data. All processing happens client-side via native browser APIs.

How to use HMAC Generator

  1. 1

    Open the tool

    Open HMAC Generator directly — no signup or installation required. The interactive interface loads instantly.

  2. 2

    Paste or enter your input

    Drop your data into the input area. The tool validates and processes your input live as you type or paste.

  3. 3

    Review the result

    The output updates instantly. If the tool has configuration options, adjust them and watch the result update.

  4. 4

    Copy or download

    Use the copy button to send the result to your clipboard. Nothing is saved between page loads, so closing the tab discards everything.

Frequently asked questions

Is any data sent to a server?
No. The tool runs entirely in your browser using native JavaScript and Web APIs. Nothing you paste or upload is transmitted, logged, or stored. You can verify this by disconnecting your network and seeing the tool continue to work.
Is this tool free to use?
Yes. It's completely free with no login, signup, API key, or usage limits. Catalyst is funded by ads and will remain free forever.
Does it work offline?
Once the page has loaded, yes. All processing happens locally in your browser, so you can use the tool on airplanes, trains, or in air-gapped environments.

Related tools

Hash Generator
Hash & Security
JWT Builder and Signer
Hash & Security
Password Generator
Hash & Security