Hi air2water,

Don't you just hate it when that happens .....

I'm a 'Windows person', I hope this will work on Mac as well :

Let's try this :

Open Firefox and press Ctrl +L (whichwill put the focus into the location bar)

Type about:config

Press Enter twice

Type devpix

Press the Tab key

Press Enter

Type 1.0

Press Enter again, and with a bit of luck you should be able to see what you're doing again (fingers crossed) .......

I tried that 20 times because I saw another post. On a Mac you need to hit command+L to put focus into location bar. Got so frustrated I deleted Firefox and am using Safari right now. I really liked Firefox, if I could only figure a way to see it. I am not even sure what shows up when I open Firefox because it is so tiny.

air2water said

I tried that 20 times because I saw another post. On a Mac you need to hit command+L to put focus into location bar. Got so frustrated I deleted Firefox and am using Safari right now. I really liked Firefox, if I could only figure a way to see it. I am not even sure what shows up when I open Firefox because it is so tiny.

Ahhh, of course : on Mac it's not 'Ctrl', but 'Cmnd' (sorry  !)

So, you had tried that already and it didn't work - well, again : my bad, cause when you said that everything was as big as your thumb, I was thinking : huge .....

Probably a rhetorical (and maybe even dumb) question : but have you tried to use the keys on your keyboard to zoom in  ?

'Found this :

https://alvinalexander.com/blog/post/mac-os-x/how-zoom-in-zoom-out-mac-osx-screen

If that doesn't at least get you back to being able to resetting the prefs on the 'about:config' page, then I can only hope that somebody else will be able to come up with the perfect solution for you .....

I got a magnifying glass and was able to barely see about:config. I reset the line ( layout.css.devPixelsPerPx) I am now back in business. Thanks so much for the help. Firefox--here we come.

that you can also edit the prefs.js file in the profile folder and edit/remove the offending line if this happens again.

The Firefox profile folder is in a hidden location in the home directory.

• ~/Library/Application Support/Firefox/Profiles/<profile>/

In Mac OS X v10.7 and later, the ~/Library folder in the Home directory is a hidden folder.

• http://kb.mozillazine.org/Show_hidden_files_and_folders#Mac_OS_X

Murphy said

... have you tried to use the keys on your keyboard to zoom in  ?

I like Murphy's suggestion:

While you're on the about:config page, hold down Command and tap the + key repeatedly to enlarge it as much as Firefox can enlarge (300%, I think). Hopefully then it will be readable and you can reset the problem setting. Then press Command+0 to restore normal zoom on the page.

But anyway, the magnifying glass works, too.