Scroll Zoom от Armin Sebastian

Scroll Zoom is a Firefox extension which lets you zoom web pages by holding the left or right (default) mouse button and moving the scroll wheel. The mouse gestures can be configured from the extension's options, and the customization of zoom levels is also supported.

The continued development of Scroll Zoom is made possible thanks to the support of awesome backers. If you'd like to join them, please consider contributing with Patreon, PayPal or Bitcoin.

Due to browser restrictions the extension does not work on the Firefox Add-ons website or local browser and extension pages, such as about:addons. Zooming is only possible for tabs containing a HTML or XML document, the mouse gesture will have no effect on PDF, TXT or JSON documents.

The extension is also available for Chrome and Edge.

Reviews are not monitored for bug reports, please use GitHub for issues and feature requests.
https://github.com/dessant/scroll-zoom