If you’re running Windows 7 and you don’t know already, please select Display from the Control Panel and see if you’re set to Medium (125%) or Smaller (100% default). I’m set to the non-default (“Medium”) but don’t recall doing this – perhaps I set it that way several years ago and forgot, or maybe the computer shop that configured and sold the laptop to me chose it as a preferable default. Either way, I’m happy. I’ve grown used to the larger fonts and icons that Windows presents, and the two programs I use most: Chrome and Cygwin – mostly ignore the Windows Display setting. (Some of the Chrome menus, etc. are subject to the Display setting, just not displayed webpages themselves.)
But Firefox does not ignore the Windows display setting. With “Medium,” Firefox-displayed fonts and images will all be 25% larger, it seems. (Or not? Do some, but not most, websites’ CSS bypass this Firefox “feature”?)
For many years now, Firefox has been displaying everything 25% larger for me and I barely knew it! I was dimly aware, but didn’t really care. I use Chrome for almost everything, and for the “special needs” that lead me to use Firefox, I was aware that the “look-and-feel” was quite different but never bothered to comprehend that it was a simple 25% bigger thing. :smack: (Finally I got around to caring, did a Google, and discovered the Control Panel–>Display–>Medium thingamagoo.)
My questions are: Are website developers well aware of this Firefox-Chrome difference? Do most users simply avoid the issue by keeping the “Smaller” setting? To me, it seems like one of these user-friendly computer gotchas that I find annoying.
(I’m keeping the Medium" setting, but will do a Zoom Out on Firefox to make it like Chrome. I’ve grown used to the larger fonts for Windows popups and icons.)
I can’t answer the questions about browsers but I do know how your laptop got set to Medium - Windows did it automatically when it was installed. If the resolution of your screen is over a certain threshold (I don’t recall the exact numbers) Windows will set the font size to Medium so that fonts aren’t too small to read. Microsoft did this because they found that a lot of people would set their screen resolution to something less than the optimal resolution because they couldn’t read words on the screen. LCD displays are meant to be used at their native resolution. Using them at a lower resolution tends to make things blurry. People who lowered the resolution to make words more readable complained that other things were less crisp so Microsoft made this change in the installer to use bigger fonts on high-resolution displays.
Thanks for the answer, Gus. I’m not surprised: on my machine Windows text and icons seem bizarrely small and horrid at the “Smaller (default)” setting.
I posted just because it seemed odd that it wasn’t a more well-known confusion. But “firefox display larger than chrome” gets 2.5 million Google hits, so the issue isn’t unheard of. 
Thank you for this. As the years go by it seems that the text on the monitor got smaller and smaller. I’m way more comfortable now.
Wow thanks for that! It helps a lot. I wish though that the little box here for typing responses would be more embiggened as well.
In Firefox you can just hit <cntl> + or <cntl>- to change font size. Is this not well-known?
Same in IE since about version 4 in 2001.
As an user help guy I can assure you it is not. They do not teach that in schools. :dubious: There is even more simple solution that works in all modern browsers and some other apps: <ctrl> + scroll button on mouse. Works on macs too.
I guess it wasn’t as well-known as you thought.
I don’t know what the added relevance is to this thread. I was obviously aware of it, though writing “Zoom Out on Firefox” instead of the equivalent “<cntl>-.” And, BTW, images change size as well as fonts.
The point is that Firefox’s default size (also the “reset” size) will be affected by the Windows option. IOW, with the Windows Medium option (which others agree is mandatory to get good display on some screens) Chrome and Firefox will display at different sizes from each other unless you use the Zoom controls.
No big deal, I suppose. But I was surprised there was such a big built-in difference in browser display and wondered how website developers coped.