Fullscreen Firefox on two screens

Question

I want to use a program (Firefox) in full-screen mode on two screens for presenting. Like a "Kiosk".

When I press F11, Firefox goes to full screen, but only on one screen.

Answer 1

You need some solutions to make the OS recognizes the two (or more) screens as one like AMD's Eyefinity. Other alternatives being UltraView Desktop Manager and DisplayFusion

DisplayFusion has hotkey support for window movement, snapping to the sides of the monitors, maximization to span all monitors, and the ability to size windows to a percentage of the work area.

Make the Most of Your Multiple Monitors in Windows

• How do I make 2 monitors appear as 1 (Stretch Screen)
• How To Split a 4K Monitor or Divide an Ultrawide Monitor Into Multiple Virtual Monitors
• How To Transform Multiple Small Screens Into One Giant Display
• How to set up a Video Wall in Ventuz

You didn't specify the OS, but if it's Windows then this is possibly a duplicate of

• Make computer use 2 monitors as 1
• Maximize program across multiple monitors
• How can you maximize a window on to dual monitors in Windows?

For other OSes

• Rendering a single fullscreen window across multiple monitors
• How to span a window between two displays in Mavericks
• Mac: How to span windows across multiple displays
• command to span window across multiple monitors

You can also use autoit, autohotkey or any other available scripting language to resize the window to span across monitors

Answer 2

i was able to get F11-maximized windows over 3 unified displays using NVidia Mosaic with a Quadro GPU