ModuleNotFoundError: No Module Named ‘webdriver_manager’

ModuleNotFoundError: No module named 'webdriver_manager' is usually one of two things: you installed it under the wrong name, or you installed it into a different Python than the one running your script. There is also a third possibility worth checking first — since Selenium 4.6, you probably do not need this package at all.

The fix#

python -m pip install webdriver-manager

from webdriver_manager.chrome import ChromeDriverManager

Hyphen when installing, underscore when importing. This mismatch is normal in Python — the name on PyPI and the importable module name are set independently — but it catches almost everyone once.

Check you do not need it#

Selenium 4.6 and later include Selenium Manager, which downloads and matches the correct driver automatically. For most projects that removes the dependency entirely:

from selenium import webdriver

driver = webdriver.Chrome()          # driver handled for you
driver.get("https://example.com")
print(driver.title)
driver.quit()

python -m pip install --upgrade selenium
python -c "import selenium; print(selenium.__version__)"

If that version is 4.6 or higher, delete the webdriver-manager import and the Service boilerplate around it. One less dependency and one less thing to break.

Using it when you still need it#

There are legitimate reasons to keep it — an older Selenium you cannot upgrade, or a locked-down environment where you want explicit control over driver caching.

from selenium import webdriver
from selenium.webdriver.chrome.service import Service
from webdriver_manager.chrome import ChromeDriverManager

service = Service(ChromeDriverManager().install())
driver = webdriver.Chrome(service=service)

driver.get("https://example.com")
print(driver.title)
driver.quit()

For Firefox and Edge the pattern is identical:

from webdriver_manager.firefox import GeckoDriverManager
from selenium.webdriver.firefox.service import Service as FirefoxService

driver = webdriver.Firefox(service=FirefoxService(GeckoDriverManager().install()))

When installing did not help#

The install almost certainly succeeded — into a different interpreter. Check both sides:

python -c "import sys; print(sys.executable)"
python -m pip show webdriver-manager

If pip show finds nothing while a bare pip show does, that is the mismatch. Always install with python -m pip.

Inside a virtual environment, globally installed packages are invisible by design:

python -m venv .venv
source .venv/bin/activate        # .venv\Scripts\activate on Windows
python -m pip install selenium webdriver-manager

In VS Code, open the command palette and run “Python: Select Interpreter” to point the editor at the same environment your terminal uses.

Running without a visible browser#

from selenium import webdriver
from selenium.webdriver.chrome.options import Options

options = Options()
options.add_argument("--headless=new")
options.add_argument("--no-sandbox")
options.add_argument("--disable-dev-shm-usage")

driver = webdriver.Chrome(options=options)

The last two arguments matter inside Docker and CI, where the default shared-memory size is too small and Chrome crashes without an obvious message.

Waiting properly#

from selenium.webdriver.common.by import By
from selenium.webdriver.support.ui import WebDriverWait
from selenium.webdriver.support import expected_conditions as EC

wait = WebDriverWait(driver, 10)
element = wait.until(EC.presence_of_element_located((By.CSS_SELECTOR, "h1")))
print(element.text)

Almost every flaky Selenium test comes from acting before the page is ready. Explicit waits like this are the fix; time.sleep() is the thing they replace.

Where to go next#

• Python virtual environments — the cause of most install mismatches.
• Web scraping and automation — when requests would be simpler than a browser.
• Fixing ModuleNotFoundError — the same diagnosis in depth.