Is it possible to run selenium (Firefox) web driver without a GUI?

Question

What you're looking for is a headless-browser.

Yes, it's possible to run Selenium on Firefox headlessly. Here is a post you can follow.

Here is the summary steps to set up Xvfb

#install Xvfb
sudo apt-get install xvfb

#set display number to :99
Xvfb :99 -ac &
export DISPLAY=:99    

#you are now having an X display by Xvfb

Chrome now has a headless mode:

op = webdriver.ChromeOptions()
op.add_argument('--headless')
driver = webdriver.Chrome(options=op)

Yes. You can use HTMLUnitDriver instead for FirefoxDriver while starting webdriver. This is headless browser setup. Details can be found here.

If you want headless browser support then there is another approach you might adopt.

https://github.com/detro/ghostdriver

It was announced during Selenium Conference and it is still in development. It uses PhantomJS as the browser and is much better than HTMLUnitDriver, there are no screenshots yet, but as it is still in active development.

An optional is to use pyvirtualdisplay like this:

from pyvirtualdisplay import Display

display = Display(visible=0, size=[800, 600])
display.start()

#do selenium job here

display.close()

A shorter version is:

with Display() as display:
    # selenium job here

This is generally a python encapsulate of xvfb, and more convinient somehow.

By the way, although PhantomJS is a headless browser and no window will be open if you use it, it seems that PhantomJS still needs a gui environment to work.

I got Error Code -6 when I use PhantomJS() instead of Firefox() in headless mode (putty-connected console). However everything is ok in desktop environment.

UPDATE: You do not need XVFB to run headless Firefox anymore. Firefox v55+ on Linux and Firefox v56+ on Windows/Mac now supports headless execution.

I added some how-to-use documentation here:

https://developer.mozilla.org/en-US/Firefox/Headless_mode#Selenium_in_Java