SessionNotCreatedException: This version of ChromeDriver only supports Chrome version 114

undetected-chromedriver auto-downloaded a ChromeDriver that does not match your installed Chrome major version. Pass your Chrome's major version explicitly: uc.Chrome(version_main=114) (replace 114 with yours, from Chrome menu -> Help -> About Google Chrome). It then downloads the matching driver and the session starts.

The error

SessionNotCreatedException: This version of ChromeDriver only supports Chrome version 114

Fix it

1. Find your installed Chrome's major version

Open Chrome menu -> Help -> About Google Chrome, or run:

google-chrome --version

Expected: something like Google Chrome 138.0.7204.101. The major version is 138.

1. Pin the driver to it

import undetected_chromedriver as uc
driver = uc.Chrome(version_main=138)  # your major version from step 1

Expected: the session starts with no SessionNotCreatedException.

1. Alternative: update Chrome itself

If you would rather move Chrome forward than pin the driver, update Chrome to the latest and call uc.Chrome() with no arguments. Expected: auto-downloaded driver and fresh Chrome agree.

When this applies

• the error names two different Chrome versions (supported vs current)
• Chrome auto-updated overnight and the scraper broke
• undetected-chromedriver downloaded the driver itself (you never placed one manually)

When it does NOT apply

• cannot find Chrome binary means Chrome is not installed at all
• 'chromedriver' executable needs to be in PATH is plain selenium without undetected-chromedriver

Compatibility

undetected-chromedriver 3.x with any Chrome. The version_main parameter exists across 3.x releases.

Variant phrasings

selenium.common.exceptions.SessionNotCreatedException: Message: session not created: This version of ChromeDriver only supports Chrome version N

The same mismatch as wrapped by newer selenium. Same fix.

Why it happens

Chrome and ChromeDriver must share a major version. undetected-chromedriver downloads whatever driver is current at first run and caches it; when Chrome later updates (or the cache was built for a different Chrome), the cached driver refuses the session. version_main forces a download matching the Chrome you actually have.

Edge cases

• The driver cache lives in a user folder. Deleting the cached driver and re-running also forces a fresh download, but version_main is the deterministic fix.
• In CI, pin both: install a fixed Chrome version AND pass the same version_main, so neither side drifts.
• Brave and other Chromium forks report their own versions. Use the fork's major version the same way.