Mozilla DPI Issues on Unix

What do I do if fonts look too big or too small in seamonkey ?

We have some known issues with dpi settings -- gecko, unlike previous browsers, sets fonts according to the X server's dpi settings.

To find out what your server thinks your dpi settings are, run the program xdpyinfo:

$ xdpyinfo | grep resolution

Check the dimensions in pixels and millimeters and the resolution in dpi. Compare to what you're actually using.

If the values are significantly different, then your X server is confused about your monitor size. You can work around that temporarily for mozilla, by setting an environment variable:

setenv GECKO_FONT_SIZE_FACTOR 1.75

Or you can fix the server's dpi by doing one of the following:

1. If you use the graphical login screen:
   

   $ su - root
   $ xemacs /etc/X11/xdm/Xservers
       

   Change:

   :0 local /usr/X11R6/bin/XSomething

   to

   :0 local /usr/X11R6/bin/XSomething -dpi 100

   You need to restart xdm for this to work.

   $ su - root
   $ telinit 3
   $ telinit 5
       

2. If you use Redhat and use gdm:
   

   $ su - root
   $xemacs /etc/X11/gdm/gdm.conf
         

   Change:

   0=/usr/bin/X11/X

   to

   0=/usr/bin/X11/X -dpi 100

   You will need to restart gdm for this to work

3. If you startx from the command line:
   

   $ startx -- -dpi 100
       

4. As a last resort
   

   Edit your prefs.js file and add

   user_pref("browser.screen_resolution", 120);

   You may change the number to any resolution you like, or to 0 to use the Xserver dpi.