Selenium SessionNotCreatedException — ChromeDriver Version Error
This post explains how to fix the SessionNotCreatedException error in Selenium caused by a ChromeDriver version mismatch, and how to use webdriver-manager so the correct driver version is always selected automatically.
[01] The Problem — ChromeDriver Version Mismatch
When you run a Selenium script that calls webdriver.Chrome(), you may encounter an error like the following:
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options = webdriver.ChromeOptions()
options.add_experimental_option('excludeSwitches', ['enable-logging'])
browser = webdriver.Chrome(options=options)
Figure 1. SessionNotCreatedException — the installed ChromeDriver version does not match the installed Chrome browser version.
The error message usually reads:
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selenium.common.exceptions.SessionNotCreatedException:
Message: session not created: This version of ChromeDriver only supports Chrome version XX
Current browser version is YY.Z.AAAA.BB
Why This Happens
Selenium’s webdriver.Chrome() requires a separate ChromeDriver binary that must match the major version of your installed Chrome browser. Chrome updates automatically and silently in the background, so the locally installed ChromeDriver quickly falls out of sync. The table below shows what triggers the mismatch:
| Event | Effect |
|---|---|
| Chrome auto-updates to a new major version | ChromeDriver becomes incompatible overnight |
| You install Chrome for the first time without downloading ChromeDriver | No driver binary found at all |
| You manually downloaded ChromeDriver months ago | ChromeDriver version is stale |
| You deploy to a new machine with a different Chrome version | Hard-coded driver path breaks |
How to Find Your Current Chrome Version
Before fixing the issue it is useful to confirm the installed Chrome version:
-
Windows: Open Chrome →
⋮menu → Help → About Google Chrome - macOS: Chrome menu → About Google Chrome
- Linux (Ubuntu/Debian):
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google-chrome --version
# Example output: Google Chrome 124.0.6367.201
The first number (124 in the example) is the major version. ChromeDriver must share the same major version number.
[02] Solution — webdriver-manager for Automatic Version Matching
Manually downloading and updating ChromeDriver is error-prone. The webdriver-manager library solves this entirely: it queries the ChromeDriver release API, downloads the correct driver for your installed Chrome version, and caches it locally.
Step 1 — Install webdriver-manager
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pip install webdriver-manager
Step 2 — Update Your Selenium Script
Replace the plain webdriver.Chrome() call with one that uses ChromeDriverManager().install():
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from selenium import webdriver
from webdriver_manager.chrome import ChromeDriverManager
from selenium.webdriver.chrome.service import Service
options = webdriver.ChromeOptions()
options.add_experimental_option('excludeSwitches', ['enable-logging'])
service = Service(ChromeDriverManager().install())
browser = webdriver.Chrome(service=service, options=options)
Note: Selenium 4.x introduced the
Serviceobject. Passing the driver path directly as the first positional argument (the Selenium 3 style) still works but is deprecated.
On first run webdriver-manager prints the driver download progress to the console. Subsequent runs use the cached binary unless Chrome has updated.
What webdriver-manager Does Internally
| Step | Detail |
|---|---|
| Reads installed Chrome version | Queries the local Chrome binary for its version string |
| Fetches matching ChromeDriver | Downloads from the official ChromeDriver release endpoint |
| Caches the binary | Stores under ~/.wdm/ (or %USERPROFILE%\.wdm\ on Windows) |
| Auto-updates | Re-downloads if the cached version no longer matches Chrome |
[03] Troubleshooting
| Symptom | Likely Cause | Fix |
|---|---|---|
SessionNotCreatedException persists after installing webdriver-manager |
Old-style call without Service object |
Use Service(ChromeDriverManager().install()) as shown above |
WebDriverException: ChromeDriver only supports Chrome version XX |
webdriver-manager cached an old driver |
Delete ~/.wdm/ and re-run the script |
ModuleNotFoundError: No module named 'webdriver_manager' |
Package not installed in active environment | Activate your virtualenv, then run pip install webdriver-manager
|
| Script hangs on driver download in CI/offline environment | No internet access to download driver | Pre-download the driver and pass the path directly with Service('/path/to/chromedriver')
|
| Chrome opens but immediately closes | ChromeDriver version matched but Chrome binary path is wrong | Set options.binary_location to the explicit Chrome install path |