How to use a proxy with a login and password in Selenium (Python)

What you need

The proxy is issued in the format host:port:login:password. The task: send a request through such a proxy from an automated Chrome.

Example

If the task allows changing tools, move it to Playwright for Python. It can go through an HTTP proxy with a login and password, and the code is similar to Selenium: open a page and read the text.

pip install playwright
playwright install chromium

from playwright.sync_api import sync_playwright

with sync_playwright() as p:
    browser = p.chromium.launch(
        proxy={
            # The proxy scheme is http:// even for HTTPS sites
            "server": "http://HOST:PORT",
            # Login and password in separate fields, no need to encode them
            "username": "LOGIN",
            "password": "PASSWORD",
        }
    )
    page = browser.new_page()
    page.goto("https://api.ipify.org", timeout=30000)

    # The service returns the address the request came from
    print(page.inner_text("body"))

    browser.close()

If SOCKS5

For Selenium, SOCKS5 with a login and password is likewise not confirmed by the documentation. Use Playwright with the proxy's HTTP port, as in the example.

Common errors

1. A login and password prompt appears or error 407: Chrome did not receive the proxy credentials. This is a limitation, not a bug in your code.
2. Timeout or ERR_PROXY_CONNECTION_FAILED: check HOST and PORT and whether you put the SOCKS5 port into HTTP mode.
3. Special characters in the password: in Playwright, username and password are passed in separate fields and need no encoding. Do not put the login and password into the --proxy-server address.
4. The https:// scheme in the proxy address: the issued proxy works over HTTP, so write http://HOST:PORT.