Can a website detect when you are using Selenium with Chrome driver?

I’ve been testing out Selenium with Chromedriver and I noticed that some pages can detect that you’re using Selenium even though there’s no automation at all. Even when I’m just browsing manually just using chrome through Selenium and Xephyr I often get a page saying that suspicious activity was detected. I’ve checked my user agent, and my browser fingerprint, and they are all exactly identical to the normal chrome browser.

When I browse to these sites in normal chrome everything works fine, but the moment I use Selenium I’m detected.

In theory chromedriver and chrome should look literally exactly the same to any webserver, but somehow they can detect it.

If you want some testcode try out this:

from pyvirtualdisplay import Display
from selenium import webdriver

display = Display(visible=1, size=(1600, 902))
display.start()
chrome_options = webdriver.ChromeOptions()
chrome_options.add_argument('--disable-extensions')
chrome_options.add_argument('--profile-directory=Default')
chrome_options.add_argument("--incognito")
chrome_options.add_argument("--disable-plugins-discovery");
chrome_options.add_argument("--start-maximized")
driver = webdriver.Chrome(chrome_options=chrome_options)
driver.delete_all_cookies()
driver.set_window_size(800,800)
driver.set_window_position(0,0)
print 'arguments done'
driver.get('http://stubhub.com')

If you browse around stubhub you’ll get redirected and ‘blocked’ within one or two requests. I’ve been investigating this and I can’t figure out how they can tell that a user is using Selenium.

How do they do it?

EDIT UPDATE:

I installed the Selenium IDE plugin in Firefox and I got banned when I went to stubhub.com in the normal firefox browser with only the additional plugin.

EDIT:

When I use Fiddler to view the HTTP requests being sent back and forth I’ve noticed that the ‘fake browser’s’ requests often have ‘no-cache’ in the response header.

EDIT:

results like this Is there a way to detect that I’m in a Selenium Webdriver page from Javascript suggest that there should be no way to detect when you are using a webdriver. But this evidence suggests otherwise.

EDIT:

The site uploads a fingerprint to their servers, but I checked and the fingerprint of selenium is identical to the fingerprint when using chrome.

EDIT:

This is one of the fingerprint payloads that they send to their servers

{"appName":"Netscape","platform":"Linuxx86_64","cookies":1,"syslang":"en-US","userlang":"en-US","cpu":"","productSub":"20030107","setTimeout":1,"setInterval":1,"plugins":{"0":"ChromePDFViewer","1":"ShockwaveFlash","2":"WidevineContentDecryptionModule","3":"NativeClient","4":"ChromePDFViewer"},"mimeTypes":{"0":"application/pdf","1":"ShockwaveFlashapplication/x-shockwave-flash","2":"FutureSplashPlayerapplication/futuresplash","3":"WidevineContentDecryptionModuleapplication/x-ppapi-widevine-cdm","4":"NativeClientExecutableapplication/x-nacl","5":"PortableNativeClientExecutableapplication/x-pnacl","6":"PortableDocumentFormatapplication/x-google-chrome-pdf"},"screen":{"width":1600,"height":900,"colorDepth":24},"fonts":{"0":"monospace","1":"DejaVuSerif","2":"Georgia","3":"DejaVuSans","4":"TrebuchetMS","5":"Verdana","6":"AndaleMono","7":"DejaVuSansMono","8":"LiberationMono","9":"NimbusMonoL","10":"CourierNew","11":"Courier"}}

Its identical in selenium and in chrome

EDIT:

VPNs work for a single use but get detected after I load the first page. Clearly some javascript is being run to detect Selenium.

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You can try to use the parameter “enable-automation”

var options = new ChromeOptions();

// hide selenium
options.AddExcludedArguments(new List<string>() { "enable-automation" });

var driver = new ChromeDriver(ChromeDriverService.CreateDefaultService(), options);

But, I want to warn that this ability was fixed in ChromeDriver 79.0.3945.16. So probably you should use older versions of chrome.

Also, as another option, you can try using InternetExplorerDriver instead of Chrome. As for me, IE does not block at all without any hacks.

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