Firefox supports command-line arguments to specify URL, height and width. For example:
firefox -height 600 -width 800 "example.com"
Depending on your setup, that might actually open in new tabs. Use -new-window "example.com"
to force a new window.
Do note that these windows will actually launch under a single process, reusing one if FF is already open. Apparently, setting the size will not work unless you're starting a new process (see the comments). You must specify -no-remote
in order to launch multiple independent processes, and each must use a different profile, which you can specify with -p "profilename"
. Profiles must be created before use.
For example, if you were to do this in a loop (bash):
for i in do firefox -no-remote -createprofile testprofile$i firefox -no-remote -p testprofile$i -height 600 -width 800 "example.com"& done
(The &
is at the end to run it in the backround, i.e. don't wait for it to close.)