selenium sessionnotcreatedexception: this version of chromedriver only supports chrome version

TL;DR

Chromedriver and Chrome must share the same major version; when Chrome auto-updates, a pinned driver stops working. The durable fix is to stop pinning: let Selenium Manager (built into Selenium 4.6 and newer) download the matching driver automatically, or pin both versions together.

Error

selenium.common.exceptions.SessionNotCreatedException: Message: session not created: This version of ChromeDriver only supports Chrome version 120
Current browser version is 124.0.6367.60

Steps

1. Check both versions: chromedriver --version and google-chrome --version. Expected: you see the mismatch, e.g. driver 120 against browser 124.
2. Easiest fix: remove any hardcoded driver path from your code and let Selenium Manager resolve it (Selenium 4.6 and newer does this when no driver path or Service is given). Expected: the next run downloads the matching driver automatically.
3. If you manage the driver yourself, install the matching release: npm i -D chromedriver@124 to match Chrome 124, or fetch it from the Chrome for Testing distribution. Expected: chromedriver --version prints the same major as Chrome.
4. Pin both in CI: use a Docker image or setup action that installs a matched pair, so Chrome cannot drift ahead of the driver. Expected: CI stops breaking on Chrome auto-updates.
5. Re-run the suite. Expected: the session creates without SessionNotCreatedException.

When to use

• The error names the Chrome version chromedriver supports.
• It broke right after a Chrome update, with no code change.
• It fails in CI but works locally (different Chrome versions).

When not to use

• Renderer timeouts (the session exists; the page hangs).
• Element-not-found errors (selector issue).
• chromedriver executable needs to be in PATH (driver missing, not mismatched).

Tool compatibility

• Selenium 4.x; Chrome and Chromedriver 115 and newer (the Chrome for Testing era).
• Selenium Manager needs network access to the driver download endpoints.

Variant phrasings

Current browser version is X with a different number

Same fix regardless of which side is newer: align the majors.

chromedriver 114 against Chrome 115 or newer

Version 115 moved drivers to the Chrome for Testing distribution and broke old download URLs. Use the new distribution.

works locally, fails in CI

The CI image has a different Chrome than your laptop. Pin the pair in the image.

Why it happens

Chromedriver speaks the DevTools protocol of one Chrome major version. Chrome auto-updates silently, so a driver that worked yesterday mismatches today. Version 115 also moved drivers to the Chrome for Testing distribution, which broke old download URLs on top of the version skew.

Edge cases

• Selenium Manager caches drivers under the selenium cache dir in your home folder; clear it if it cached a stale one.
• Corporate proxies can block the driver download; then pin the driver manually instead.
• A chromedriver found on PATH shadows Selenium Manager's copy, so check PATH first when the auto-download seems ignored.

Provenance

Resolved from the public thread: https://vectle.com/posts/pst_8qKzt0PaWF-q3477tfOFsg