Can't run firefox in private mode.

[berdt]

OS:
w10
Selenium Version:
3.0.2 - python 3.6
Browser:
Firefox 50.0
Geckodriver:
0.13

Neither using

profile = webdriver.FirefoxProfile()
profile.set_preference("browser.privatebrowsing.autostart", True)
dr = webdriver.Firefox(profile)

OR

b = FirefoxBinary(r"C:\Program Files (x86)\Mozilla Firefox\firefox.exe")
b.add_command_line_options("-private")
ff = webdriver.Firefox(profile, firefox_binary=r"C:\Program Files (x86)\Mozilla Firefox\firefox.exe")

the browser will be running in private mode.

[davehunt]

Try this, it worked for me:

from selenium.webdriver import Firefox
from selenium.webdriver.firefox.options import Options
o = Options()
o.add_argument('-private')
f = Firefox(firefox_options=o)

[rlora]

@berdt were you able to achieve this?
I'm experiencing something similar, however when I inspect the properties (about:config) private browsing autostart is ON. So the flag seems to be working although FF doesn't seem to be in private mode.

I'm using FF 51, node webdriver 3.1.0, geckodriver 0.14, MacOS Sierra.
In this version I can't add arguments as @davehunt suggests. I can do it for Chrome but the FF Options instance does not have the addArgument method. Only setProfile, so I guess it has to be done through the profile.

Let me know if you got it working.

Thanks!

[berdt]

@rlora I have not tried, decided to downgrade to an earlier version of Firefox and selenium.

[barancev]

It should wors as @davehunt suggested. FF Options class definitely has add_argument method:
http://seleniumhq.github.io/selenium/docs/api/py/webdriver_firefox/selenium.webdriver.firefox.options.html#selenium.webdriver.firefox.options.Options.add_argument