This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Mouse keeps changing font sizes up and down when scrolling.

  • 1 nzaghachinzaghachi
  • 1 nwere nsogbu anwere nsogbu a
  • 27 views
  • Nzaghachi ikpeazụ nke cor-el

more options

When scrolling with my mouse, the font sizes change up and down. I can't control it - when the fonts get really small how do I adjust the size back to a readable size. In Explorer I could change the size of the font all the time but here I can't find where to do it. I've changed the font in the Options but that becomes null when I use my mouse.

When scrolling with my mouse, the font sizes change up and down. I can't control it - when the fonts get really small how do I adjust the size back to a readable size. In Explorer I could change the size of the font all the time but here I can't find where to do it. I've changed the font in the Options but that becomes null when I use my mouse.

All Replies (1)

more options

Zooming the page when you rotate the mouse wheel would normally only happen if you hold down the Ctrl key.

It is possible that some of the status keys have the wrong state and Firefox sees them as still pressed.

Try to press all the status keys (Shift, Ctrl, Alt) a few times to see if that helps to recover from this. If it doesn't help then close and restart Firefox or reboot the computer.

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem.

  • Switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance
  • Do NOT click the Reset button on the Safe Mode start window

You can set mousewheel.with*.action prefs like the mousewheel.withcontrol.action pref (on Mac mousewheel.with_meta.action) prefs to 1 on the about:config page to avoid zooming if the Ctrl/Command key is pressed.

You can open the about:config page via the location/address bar. You can accept the warning and click "I'll be careful" to continue.

You can also try a different mouse and check the settings in the mouse driver (Windows Control Panel).