How to invert mouse scroll wheel zoom direction in Firefox?

Question

When scrolling down the mouse wheel with CTRL, the zoom decreases. I would like it to increase when I scroll down, and vice versa.

Is there a way to change it?

Answer 1

Open about:config and set the preference:

For Firefox 17+:

mousewheel.with_control.delta_multiplier_y = -100 // default 100

For Firefox <=16:

mousewheel.withcontrolkey.numlines = -1 // default 1