What do you mean by "open the web page in kiosk mode"?

Did you start Firefox with the --kiosk parameter?

Are you using Windows?

Yes, I am using Windows 11.

And yes, I more or less mean starting Firefox with the --kiosk parameter. I say "more or less" because I already had a lot of Firefox windows and tabs open, so I didn't exactly start Firefox. What I did was use Run to execute a "firefox --kiosk <URL>" command, and it opened a new tab in an existing Firefox window.

I did manage to find a somewhat ridiculous solution. I opened Task Manager and selected "End task" for Firefox. Then I restarted Firefox. Luckily, it came up with the "Restore session" option. And after I restored my session, all the windows and tabs were behaving normally. So that's the only way I know of to exit kiosk mode.

Do you know of any other way Firefox users can open webpages in fullscreen mode? Kiosk mode is far more trouble than it's worth.

You can press F11 to put any web page in full screen.

Kiosk mode is designed for a very specific use case and shouldn't be used for day to day browsing.

I suppose there's been a misunderstanding. I'm not talking about putting an already opened webpage into fullscreen mode: F11 does that just fine. I'm talking about opening a webpage in fullscreen mode. Ideally, there would be a command one could run to open a webpage in fullscreen mode with Firefox, something like (if I can make up a hypothetical command) "firefox --fullscreen https://example.com" or "C:\Program Files\Mozilla Firefox\firefox.exe --fullscreen https://example.com".

Do you know how to open a webpage in fullscreen mode with Firefox? Thanks!

If you are just doing this on your own machine, you can start firefox with:

firefox -height 1600 -width 1200

Where the dimensions are the same as your screen.

We don't have the "fullscreen" command line parameter like Chrome.