Introduction

guide CAPTCHAs With Selenium, you can automate web scraping, search tasks, logging into multiple accounts, and more.

This open-source, platform independent, cross-browser, and versatile automation framework is built to save time and enhance productivity. However, one obstacle stands in the way — CAPTCHAs.

A Completely Automated Public Turing test to tell Computers and Humans Apart (CAPTCHA) is a tool used by various site owners to keep humans in and bots out.

You are right! CAPTCHAs are not friendly with Selenium. But since you are here, worry less! Take a deep dive into this piece to learn how to Bypass CAPTCHAs with Selenium.

Bypassing CAPTCHAs with Selenium

1.   Understand how different CAPTCHAs work

Before you proceed to bypass various CAPTCHAs, you ought to understand how each works. Thanks to Selenium’s support for multiple languages, you may execute the rest of the steps in your preferred coding language. For instance, you can Bypass CAPTCHAs with Selenium in Python, Java, or JavaScript.

Now, while interacting with various websites, you are likely to come across these four types of CAPTCHAs:

• Text-based CAPTCHAs: These ones present you with the challenge of recognizing and inputting pre-defined text correctly. The text is usually overlapped, warped, or blurred to make it challenging for bots to solve but easier for humans to decipher.

• Image-based CAPTCHAs: This type requires you to observe the presented pictures and select specific ones as directed. For instance, the CAPTCHA puzzle may highlight four pictures containing cars among other random photos and require you to select the four photos only. If you observe closely, you’ll realize the four photos contain cars among other elements. That’s how these CAPTCHAs are able to distinguish bots from humans. Humans are likely to solve the puzzle quickly while bots struggle to accurately identify the photos correctly due to visual complexity.

• reCAPTCHA v2/v3: Google built both v2 and v3 to aid in protecting sites from automated scripts or spam. reCAPTCHA v2 may require you to solve an image selection puzzle or just click on a checkbox saying, “I’m not a robot.” reCAPTCHA v3 runs in the background, scanning website interactions to determine whether it’s a human or bot navigating a website. It is less intrusive and effective at the same time.

• Invisible reCAPTCHA: This kind is supposed to allow for a smooth user experience while also protecting a website from bots. Like reCAPTCHA v3, it runs in the background and does not require puzzle solving or checkbox clicking. Invisible reCAPTCHA assesses user behavior like browsing patterns, mouse clicks and movements, and wait-time to conclude whether it’s a bot or human exploring the website.

2.   Explore the nature of the target site’s CAPTCHAs

To effectively bypass CAPTCHAs with Selenium, you must understand how the target site’s CAPTCHA system works. Visit the website in question and interact with it to determine what triggers CAPTCHAs or when CAPTCHAs show up.

Then, when CAPTCHAs show up, examine their nature. Are they text-based, image-based, or reCAPTCHA? Use the web browser tool to inspect the website’s source code and network requests. This helps you tell whether the website is using third-party CAPTCHA services or a custom CAPTCHA script.

Study the CAPTCHA to understand how it challenges the web visitor. Also, deliberately provide the wrong answer to see whether the challenge gets harder with time.

3.   Use Selenium to simulate human behavior in your automation script

Armed with a vivid picture of what triggers the target site’s CAPTCHAs, prepare your automation script with Selenium. Remember, the aim is to bypass the CAPTCHAs, not solve them.

So, your script must pass as a regular user and not a bot. To do this, Selenium provides you with tools to mimic the following human behavior to avoid triggering CAPTCHAs:

A.   Delays and Waits

Selenium allows you to implement waits or delays in between actions and events. You should use this feature to implement load-time waits, especially when automating interactions with a dynamic website. Your script should wait for the elements to load fully before taking the next action.

B.   Randomized clicks

Unlike humans, bots may repeatedly click on one area of a button, raising suspicion. Using Selenium, you can randomize clicks around a button’s boundary. Moreover, you should include delays in between clicks to make it look like it’s a real user interacting with the website.

C.   Mouse movements and element hovering

While bots move the mouse in a straight path or line, humans tend to move the mouse in an irregular or inconsistent path. Also, when a human points the cursor at an element, they at times hover over it while considering whether to click. Selenium is able to generate curved paths between elements and pause for a while before clicking an element.

D.   Typing and scrolling patterns

Even though Selenium can simulate typing with the help of the .send_keys() method, it inputs text instantly. To make the process human-like, you can include delays between keystrokes.

Besides mimicking human typing, you should also adjust scrolling speed or implement random scroll-pauses to improve on Selenium’s ability to scroll through a page like a human.

E.   Browser window resizing

Bots rarely resize browser windows. Humans, on the other hand, do resize browser windows from time to time to improve visibility. Selenium allows you to add this capability to your script, allowing your script  to randomly resize or maximize the browser window.

Incorporating these human-like capabilities into your automation script should see you automate web activities with little to no hiccups. However, if your script triggers CAPTCHAs even after adding these human-like layers, consider extending its capabilities to bypass even the most stubborn CAPTCHAs.

A tool like Puppeteer includes a feature called, “stealth mode” that’s capable of masking automation or the use of bots. You can use it to remove browser fingerprints and indicators that you are using a Selenium script, making it hard for CAPTCHA systems to detect your script.

Closing Words

Now that you understand how to bypass CAPTCHAs with Selenium, you can select your preferred coding language and curate a human-like script. Go automate form submissions, data entry, file downloads, web navigation, and web scraping with minimal to no worry of triggering CAPTCHAs!