Is it possible to run multiple instances of one selenium test at once?

I think you can do that. But I feel the better or easier way to do that is using different windows. Having said that we can use either multithreading or multiprocessing or subprocess module to trigger the task in parallel (near parallel).

Multithreading example

Let me show you a simple example as to how to spawn multiple tests using threading module.

from selenium import webdriver import threading import time def test_logic(): driver = webdriver.Firefox() url = 'https://www.google.co.in' driver.get(url) # Implement your test logic time.sleep(2) driver.quit() N = 5 # Number of browsers to spawn thread_list = list() # Start test for i in range(N): t = threading.Thread(name='Test {}'.format(i), target=test_logic) t.start() time.sleep(1) print(t.name + ' started!') thread_list.append(t) # Wait for all threads to complete for thread in thread_list: thread.join() print('Test completed!') 

Here I am spawning 5 browsers to run test cases at one time. Instead of implementing the test logic I have put sleep time of 2 seconds for the purpose of demonstration. The code will fire up 5 firefox browsers (tested with python 2.7), open google and wait for 2 seconds before quitting.

Logs:

Test 0 started! Test 1 started! Test 2 started! Test 3 started! Test 4 started! Test completed! Process finished with exit code 0 

Python 3.2+

Threads with their own webdriver instances (different windows)

Threads can solve your problem with a good performance boost (some explanation here) on different windows. Also threads are lighter than processes.

• You should use a concurrent.futures.ThreadPoolExecutor with each thread using its own webdriver.
• Also consider adding the headless option for your webdriver.

The example bellow uses a chrome-webdriver. To exemplify uses integer as argument url_test for the test function selenium_test 6 times.

from concurrent import futures from selenium import webdriver def selenium_test(test_url): chromeOptions = webdriver.ChromeOptions() #chromeOptions.add_argument("--headless") # make it not visible driver = webdriver.Chrome(options=chromeOptions) print("testing url {:0} started".format(test_url)) driver.get("https://www.google.com") # replace here by driver.get(test_url) #<actual work that needs to be done be selenium> driver.quit() # default number of threads is optimized for cpu cores # but you can set with `max_workers` like `futures.ThreadPoolExecutor(max_workers=...)` with futures.ThreadPoolExecutor() as executor: future_test_results = [ executor.submit(selenium_test, i) for i in range(6) ] # running same test 6 times, using test number as url for future_test_result in future_test_results: try: test_result = future_test_result.result() # can use `timeout` to wait max seconds for each thread #... do something with the test_result except Exception as exc: # can give a exception in some thread, but print('thread generated an exception: {:0}'.format(exc)) 

Outputs:

testing url 1 started testing url 5 started testing url 3 started testing url 4 started testing url 0 started testing url 2 started 

Look at TestNG, you should be able to find frameworks that achieve this.

I did a brief check and here are a couple of links to get you started:

Parallel Execution & Session Handling in Selenium

Parallel Execution using Selenium Webdriver and TestNG

If you want a reliable, rebost framework that can do parallel execution as well as load testing at scale then look at TurboSelenium : https://butlerthing.io/products#demovideo. Drop us a message and will be happy to discuss this with you.