How to start firefox in fullscreen mode?

Question

how do i start firefox 4 in fullscreen mode (the one activated by pressing f11)?

Answer 1

create a new profile by running firefox -ProfileManager

run firefox with the new profile move to full screen (F11) and then close it by ALT+F4

each time you will use this profile it will be opened in full screen

Answer 2

If you're using firefox 3 you can use this extension. It allows fullscreen on start. Tons of others do as well, see here.

I'm not aware of a command-line switch though.