Selenium: WebDriverException: unknown error: cannot find Chrome binary

ChromeDriver started, but it could not find a Chrome executable to launch. ChromeDriver looks in the default install locations for your operating system; if Chrome is installed somewhere else, is missing, or the path you supplied is wrong, the session fails with this message before any browser window opens.

It is common on servers and containers where only the driver was installed, on macOS when Chrome lives outside /Applications, on Windows with per-user installs, and on Linux distributions that install Chromium under a different name. Another frequent cause is setting binary_location to a folder instead of the executable file itself.

What is not wrong: the driver and Selenium setup. ChromeDriver is running; it just has nothing to start. If Chrome is present and found but crashes, you would see the DevToolsActivePort error instead.

from selenium import webdriver

options = webdriver.ChromeOptions()
options.binary_location = "/usr/bin/chromium"   # the executable, not its folder
driver = webdriver.Chrome(options=options)

# No Chrome installed? Let Selenium Manager fetch Chrome for Testing:
# options.browser_version = "stable"

Make the browser part of the environment definition (Dockerfile, CI image, provisioning script) rather than assuming it exists. When you must use a non-standard install, set binary_location from a single configuration value and validate the path exists at start-up, so a missing browser fails with a clear message.