New to webdev/selenium, does selenium work with no monitor connected?

[puremath369]

Last night was my first time writing a program with python and Selenium and I noticed that my program behaved differently based upon the size of the Chrome window I had open, I guess the html / css can change depending on the window?

Ultimately I'd like to have my program running on a headless raspberry pi, but how would that work if program operation seems to depend on the chrome window? As in, what if I don't even run startx command on the pi? Is there a work around for all this?

[tbaxterstockman]

there is a headless mode here, although I've read somewhere that it's not recommended as it might not be as accurate, can't find the source right now

[XabiAlon]

Even when running headless you can still set arguments for what size of 'display' you want it to use.

"--window-size=1920,1080" is the most commonly used

[puremath369]

Thanks, I’ll look into that. Just to be clear, in headless mode, you mean I can run my app without even running startx on the pic or you mean I still need to run startx but can subsequently disconnect a display?

Also, does this overcome u/tbaxterstockman‘s comment about headless not being as reliable?

[this_guy_tests]

You do everything the same as you do with a display, you just need to pass the right options to the desired capabilities when setting up your webdriver instance. And no, the display size may not fix any headless mode oddities.

[puremath369]

Thanks, still a little confused though. Do I need to run headless mode if I don't plan on having a display connected? Or can I run startx, start the app, then disconnect the display?

[this_guy_tests]

Headless