Should You Use Selenium for Web Scraping?

Web Scraping as the name implies is a technology that extracts data from websites. It is an automated process in which an application processes the HTML of a web page to extract data for processing, eg. It converts a web page to another format and then copies it to a local database or spreadsheet for later retrieval or analysis.

Many people know Selenium to be used for automation testing. However, Selenium has other use cases. An important use of Selenium is in web scraping. In this article, we will discuss whether you should be using Selenium for Web Scraping or other tools such as Beautiful Soup. Let’s begin by understanding the benefits and drawbacks of using Selenium for web scraping. 

Benefits of Using Selenium for Web Scraping

Since WebDriver uses an actual web browser to access the website, it is no different from browsing the web by a human or a robot. When you navigate to a web page with Webdriver, the browser loads all the resources of the website (JavaScript files, images, CSS files, etc.) and executes all the JavaScript on the page. It also stores all the cookies created by your websites. This makes it very difficult to determine whether a real person or a robot has accessed the website. With Webdriver this is possible in a few simple steps, however, it is really difficult to emulate all these tasks in a program that sends handcrafted HTTP requests to the server. To extract data from these browsers, Selenium provides a module called WebDriver, which is useful for performing various tasks such as automated testing, cookie retrieval, screenshot retrieval, and much more. Some common Selenium use cases for web scraping are form submission, auto-login, data addition and deletion, and alert handling. For more information about how to use Selenium for web scraping, there are many courses on selenium training online that you can enroll in for your benefit.

However, web scraping is considered to be the most reliable and efficient data acquisition method among all these methods. Web scraping, also known as the extraction of web data, is an automated process of scraping big data from websites.

Drawbacks of using Selenium for Web Scraping

As much as there are advantages to using selenium for web scraping, there must be some drawbacks. Let’s see a few of these drawbacks below.

• A large network traffic generated: Web browsers download many supplementary files that are of no value to you (such as CSS, JS, and image files). If you only request resources you really need (with different HTTP requirements) this can generate a lot of traffic.
• Scraping is easily detected with simple methods like Google Analytics: One of the drawbacks of using selenium for web scraping is, if you explore a lot of pages with Webdriver, you can easily look into JavaScript-based tracking tools (such as Google Analytics). The site owner doesn’t even need to install a sophisticated scraping detection mechanism!
• Time and  Resources Consumption: When you use WebDriver to scrape web pages you load the entire web browser into the system memory. Not only does this take time and consume system resources, but it can also cause your security subsystem to overreact (and even not allow your program to run).
• Slow Scraping Process: Since a browser waits for the entire web page to load, and only then allows you to access its elements, the scraping process can take longer than making a simple HTTP request to the webserver.

Types of Web Scraping with Selenium

There are two types of webscraping with Selenium:

1.  Static web scraping
2. Dynamic web scraping

There is a difference between static websites and dynamic websites. In static pages, the content remains the same unless someone changes them manually. On the other hand, content can move from multiple visitors to dynamic websites. For example, it can be changed according to the user profile. This increases its time complexity as a dynamic website on the client side can process a static page on the server-side while on the client side. 

The content of the static website is downloaded locally, and the corresponding scripts are used to collect the data. In contrast, dynamic website content is generated only for any number of requests during the initial load request. In order to delete the data on the website, Selenium provides some standard locators which help in locating the content of the test page. Locators are nothing more than keywords associated with HTML pages. For further details on why you should use or how to use selenium for web scraping, you can do yourself some good by getting certification on an online selenium training course to widen your horizon.

Wrapping up

The aforementioned benefits and drawbacks are not limited to the ones here. This is because Selenium website is not primarily used for the illustration of web scraping, but according to experts in web scraping, selenium is considered a strong scraping tool. It’s not that difficult to integrate them into almost every web scraping solution that is written in either Java, C#, Ruby, Python, JavaScript, or even PHP.

I hope this article is useful for making the right decision in your bid to use selenium as a web scraping tool.