Question

How can I add preferences to the browser so it launches without javascript?

Answer 1

Try setting firefox’s profile to disable the javascript:

from selenium import webdriver

fp = webdriver.FirefoxProfile()

fp.set_preference("browser.download.folderList",2)
fp.set_preference("javascript.enabled", False)

browser = webdriver.Firefox(firefox_profile=fp)

To check in the webdriver browser if javascript is enabled do the following:

On the menubar navigate to Firefox > Preferences > Content and the check button for enable javascript should be unchecked. Like the picture shown below.