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
  

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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