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I am using python to interact with webpages via selenium. I am using the geckodriver Firefox driver (not interested in Chrome solutions).

I want to zoom the browser window, equivalent to pressing ctrl+- (or cmd+- on Mac OS).

Granted, there are lots of questions on this topic. I have tried to do my due diligence in digging through them before posting here. The following are solutions that do not work for me (let driver be a WebDriver instance running with geckodriver):

No effect:

driver.execute_script("document.body.style.zoom='zoom 90%'")

from selenium.webdriver.common.keys import Keys
body = driver.find_element_by_tag_name('body')
body.send_keys(Keys.COMMAND, Keys.SUBTRACT)

from selenium.webdriver.common.action_chains import ActionChains
actor = ActionChains(driver)
actor.key_down(Keys.COMMAND).key_down(Keys.SUBTRACT).perform()

Wrong effect:

driver.execute_script("document.body.style.transform='scale(0.9)'")

driver.execute_script("document.body.style.MozTransform='scale(0.9)'")

Error:

driver.set_context("chrome")
win = driver.find_element_by_tag_name("window")
win.send_keys(Keys.CONTROL + "-")
driver.set_context("content")

(raises NoSuchElementException)

Related questions:

...and many others.

The only way I have found that actually works is to use pyautogui, however I would rather not install additional 3rd-party libraries, & I don't believe I'll be able to run this in a headless state without a lot of hassle.

However, it seems there should be some way to do this using Selenium/geckodriver's native functionality, rather than installing additional 3rd-party packages for this purpose.

Is there a way??? The abundance of questions on this topic makes it clear that I am not the only one to have had trouble with this...

EDIT: Testing on Python 3.9, Selenium 3.141.0, geckodriver 0.29.1, Firefox 90.0, Mac OS

corvus
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1 Answers1

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In Python 3.7.7, selenium 3.141.0, geckodriver 0.29.1, firefox 90.0, Ubuntu 20.04.2 LTS, I combined 2 of your items and made it work.

I could not find the window tag either, but I found body. After I got the url (and only after, otherwise I got an error), I had to do the set context to "chrome." I don't know why, but if not, as you observed, nothing happened. Then I was able to send control + or control - with the desired effect (I took two + to really see the difference, but the 110% and then 120% also shows).

driver.get(URL)#URL is a constant containing the url
driver.set_context("chrome")#needed to make keys work, must come after there is a context

win = driver.find_element_by_tag_name("body")#there is a body even if not a window
win.send_keys(Keys.CONTROL, "+")#zoom to 110%
win.send_keys(Keys.CONTROL, "+")#zoom to 120%
Jeremy Kahan
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  • driver.set_context("content") after does not cause an error. I do not know if it's needed. I also was able to run the above headless, but I cannot tell you more than that it did not cause an error (because I could not see it). Also verified works with - not just +. – Jeremy Kahan Jul 28 '21 at 07:47
  • This works for me! Thanks so much, you have no idea how mad this was making me... I must note that for me it only works with `"+"` & `"-"` but not with `Keys.ADD` or `Keys.SUBTRACT`. I am under the impression that you should include `driver.set_context("content")` afterwards unless you don't plan to interact with the webpage further – corvus Jul 28 '21 at 13:27