How to set window size in Selenium Chrome Python

Question

The following code to resize a selenium chrome window does not work:

driver.set_window_size(1920, 1080)
time.sleep(5)
size = driver.get_window_size()
print("Window size: width = {}px, height = {}px.".format(size["width"], size["height"]))

From which the output is:

Window size: width = 1044px, height = 788px

I've also tried using options to set the window size on driver creation (and lots of other things, seem comments below), but can't get it to work either:

options.add_argument("--window-size=1920,1080")

I am using selenium 3.14.0, chrome driver version 72.0.3626.109 and running in background / headless mode: I am literally needing to run my code in background, meaning it launches automatically in the background. I think there is a subtle difference between headless, which when launched is associated with a particular user, and background, which is also headless but may not be associated with a particular user and may have other idiosyncrasies - I'm starting to think this may be part of my issue.

I'd like to get chrome driver to work because firefox does not run in the background (which I need), and ie is a pain.

I want to figure this out because I can't see an element I need to click when the window is so small.

Answer 1

A bit unclear why and exactly where you are stuck. Possibly the extra . as in height = {}px. is creating the chaos. Perhaps along with -headless argument I am able to set/retrieve the Chrome browser Window Size as follows:

• Code Block:

  from selenium import webdriver
  from selenium.webdriver.chrome.options import Options
  
  options = Options()
  options.add_argument("--headless")
  options.add_argument("window-size=1400,600")
  driver = webdriver.Chrome(chrome_options=options, executable_path=r'C:\Utility\BrowserDrivers\chromedriver.exe', service_args=["--log-path=./Logs/DubiousDan.log"])
  driver.get("http://google.com/")
  print ("Headless Chrome Initialized")
  print(driver.get_window_size())
  driver.set_window_size(1920, 1080)
  size = driver.get_window_size()
  print("Window size: width = {}px, height = {}px".format(size["width"], size["height"]))
  driver.quit()
  

• Console Output:

  Headless Chrome Initialized
  {'width': 1400, 'height': 600}
  Window size: width = 1920px, height = 1080px
  

---

tl; dr

You find a couple of relevant discussion on window size in:

• python: Selenium Firefox headless returns different results
• java: Not able to maximize Chrome Window in headless mode

Answer 2

Instead of

options.add_argument("--window-size=1920,1080")

Can you please try this.

options.add_argument('window-size=1920x1080');

OR

options.add_argument("--start-maximized")

Answer 3

So I finally figured out what the problem is: Running Windows task scheduler with option 'run whether user is logged on or not' only opens a small browser (1024x768) that CANNOT be resized, even with all the great suggestions being offered here.

See the same issue resolved here: screen resolution in mode "Run whether user is logged on or not", in windows task scheduler

So the less than ideal workaround is to only run when user is logged on.