If you browse the web using Firefox on a Mac laptop you’ve probably brushed the track pad the wrong way and accidentally zoomed in on content. I’ve never used the pinch gesture to zoom in on purpose, it always happens by accident, then I have to press Command-0 to reset the screen back to normal.

I tried Googling for an answer, and found a bunch of people annoyed by the same experience, but no solutions.

I thought there might be a Firefox setting to control this, so I looked and I found one. Here’s what I did:

• I typed “about:config” into the Firefox location bar to get to the configure-anything screen.
• I clicked past the “this voids your warranty” disclaimer.
• Type “zoom” in the search bar to find settings related to zoom.
• The zoom in / zoom out gesture settings are browser.gesture.pinch.in and browser.gesture.pinch.out. Click browser.gesture.pinch.in to edit the setting. It’s usually set to “cmd_fullZoomReduce” and I changed that to “cmd_fullZoomReduce-disable”. (That way if I ever want to re-enable it all I have to do is remove the “-disable” part.)
• Click browser.gesture.pinch.out and change its setting from “cmd_fullZoomEnlarge” to “cmd_fullZoomEnlarge-disable”.

That’s it. No more annoying track pad zoom.

Hope you find this useful.