Solving Cloudflare Errors with Selenium and Undetected Chromedriver

Apr 2, 2024 ยท 3 min read

Selenium is a powerful tool for web scraping and automation. However, when faced with Cloudflare protection, it can throw errors. This is where undetected_chromedriver comes in.

What is Undetected Chromedriver?

Undetected Chromedriver is a Python package that provides a way to use Selenium with Chromium browser without being detected as a bot. It helps bypass Cloudflare and other anti-bot measures.

Common Cloudflare Errors

When using Selenium with a regular Chrome webdriver, you might encounter Cloudflare errors like:

  • "Access denied"
  • "Checking your browser before accessing"
  • CAPTCHA challenges
  • These errors occur because Cloudflare detects the automated browser.

    Using Undetected Chromedriver

    To solve these issues, we can use undetected_chromedriver instead of the regular Chrome webdriver. Here's how:

    from undetected_chromedriver import Chrome
    driver = Chrome()

    This creates a Chrome instance that appears like a regular user browser to Cloudflare.

    Benefits of Undetected Chromedriver

    Using undetected_chromedriver has several advantages:

    1. Bypasses Cloudflare anti-bot detection
    2. Reduces the chances of getting blocked
    3. Allows scraping websites protected by Cloudflare

    Headless Mode

    Undetected Chromedriver also supports headless mode, which runs the browser without a visible UI. This is useful for running scripts on servers or saving system resources.

    from undetected_chromedriver import Chrome
    options = Chrome.options()
    options.headless = True
    driver = Chrome(options=options)

    Handling CAPTCHAs

    Even with undetected_chromedriver, you might occasionally face CAPTCHA challenges. To solve them, you can:

    1. Use a CAPTCHA solving service
    2. Implement a CAPTCHA solver using image recognition
    3. Retry the request after a delay

    Here's an example of retrying after a delay:

    import time
    retry_count = 0
    while retry_count < MAX_RETRIES:
            retry_count += 1
            time.sleep(5)  # Wait for 5 seconds before retrying

    Best Practices

    When using undetected_chromedriver, follow these best practices:

  • Use a pool of IP addresses or proxies
  • Add random delays between requests
  • Rotate user agents and other headers
  • Avoid making too many requests in a short period
  • Limitations

    While undetected_chromedriver is effective, it has some limitations:

    1. It may not work for all websites
    2. Cloudflare may still detect and block the browser in some cases
    3. It is slower compared to using a regular webdriver


    Undetected Chromedriver is a valuable tool for web scraping when faced with Cloudflare protection. By mimicking a regular user browser, it helps bypass anti-bot measures and allows scraping websites that would otherwise block Selenium.

    However, it's important to use it responsibly and follow best practices to avoid getting blocked. With proper implementation, undetected_chromedriver can greatly enhance your web scraping capabilities.

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