What is the difference between pinch zoom and Ctrl + plus/minus page zoom, and how can I use both with a keyboard and mouse?

Hi there,

I am not a 100% sure what happens exactly, but it's obvious that the two methods handle the viewport differently. But Ctrl+0 should reset the view, no matter what. Does that not work? In that case, that is worth a bug report.

Unfortunately I can't attempt to reproduce it right now, but will take a second look by tomorrow if nobody else does by then.

Regards, Balázs

Pinch zoom is sometimes called magnification. The page layout does not change, but you enlarge the portion you want to see.

Proportional or reflowing zoom enlarges elements and simulates a smaller display, allowing HTML, CSS, and JavaScript to modify the layout to fit your display (for example, by switching to a mobile layout).

If you have a mouse with a scroll wheel, you may have noticed these behaviors:

• Scrolling with the Ctrl key held down: proportional zoom in or out depending on the direction you turn the wheel
• Scrolling with the Shift key held down: horizontal scrolling left or right depending on the direction you turn the wheel
• Scrolling with the Alt key held down: go "Back" or "Forward" in tab history depending on the direction you turn the wheel

Firefox has the hidden capability to assign pinch zoom to any of those key + wheel combinations instead of the default action. If you want to try that, here's how (I will use Alt as the example since I pretty much never want the scroll wheel to do anything in tab history):

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

More info on about:config: Configuration Editor for Firefox. The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.

(2) In the search box in the page, type or paste mousewheel.with*action and pause while the list is filtered

Firefox should display about 8 preferences.

(3) Double-click the mousewheel.with_alt.action preference to display an editing field, and change the value to 5 then press Enter or click the purple check mark button to save the change.

Test on a normal web page, pinch zoom doesn't work on about:config.

For reference, these are the available values:

• 0 => Do nothing
• 1 => Scroll vertically (like when no key is held down)
• 2 => Go back/forward in tab history
• 3 => Zoom in/out (reflowing zoom)
• 4 => Scroll horizontally
• 5 => Zoom in/out (pinch zoom)

If you decide that is annoying, you can use the left-arching arrow (reset button) at the right end of the row to restore the default value.

Let me know what you think.