There are a lot of articles out there that advocate for Selenium as a tool for web scraping. Experts tell people how to work around its shortcomings to get the desired result. This will not be one of those articles.
Instead, we’re going to outline why Selenium might not be the best choice if you need to scrape data. We’ll go over the weaknesses of the program, as well as some of the times it does make sense to use it.
But before we get into that, a little background.
Table of Contents
What Is Web Scraping?
Web scraping is the extraction of data from the internet at scale. It’s done automatically. Depending on the tool you use, scraping can return a trove of targeted information for analysis.
Web scraping tools in and of themselves don’t analyze data. But they can eliminate duplicates, errors, and incomplete entries from the data set they bring back. Web scrapers retrieve the information from a page by looking through its code for the things you want, or they can just pull the page’s entire code.
What Is Scraping Used For?
There are a variety of uses for web scraping. Some businesses use it for marketing, to get data on price trends or reviews, or customer demographic information. Some use scraping to analyze competitors’ web pages.
Big companies like Google use scraping all the time to glean information on people’s behavior and buying habits. That’s how you get those targeted ads that follow you around the internet.
Everyday people can also use scraping to their advantage. You could scrape the data from popular blogs or YouTube videos to see which ones do well before making your own content.
Other uses for web scraping include:
- Scraping job board sites for the highest-ranked job applications
- Scraping social media sites for user engagement data, especially for users in your niche
- Scraping Google search engine result page (SERP) data for SEO ranking tips
- Scraping big ecommerce sites for price data comparison
- Scraping ecommerce product description data for SEO information
The programs that comb the web and bring back the data are called scrapers or scraper bots. If you know how to code, you can build your own, but it’s much easier to buy one from a reputable company if you’re planning to do large-scale data scraping.
Some good web scraping rules to follow:
- If you’re using proxies, make sure they’re ethically obtained
- Don’t copy another website wholesale
- Don’t submit a deluge of requests to the page you’re scraping (it could be mistaken for an attack)
- Read the robots.txt file and abide by any request intervals you find there
You can read more on ethical web scraping practices here.
What’s Selenium and Why Do People Use It For Web Scraping?
Selenium is an open-source web development tool used to automate web browsing functions. It was developed in 2004 and is mainly used to automatically test websites and apps across various browsers.
Selenium is actually a suite of testing tools, but the tool everyone uses for web scraping is Selenium WebDriver. WebDriver is responsible for automated, cross-browser testing.
Because it’s automated, WebDriver can be used for web scraping in a similar fashion to other automated web scraping bots. You can write programming into it to make it behave like a scraper bot…but it’s better suited to testing code.
The Drawbacks of Using Selenium For Web Scraping
Selenium isn’t meant to be a web scraping tool. It was designed for automated testing. In order to use it as a scraper in the first place, you have to implement workarounds. In order to implement those workarounds, you have to know coding and programming.
As software developer Saša Buklijaš puts it this way in a blog post for Hacker Noon: “Selenium is not a web scraping tool. It is ‘for automating web applications for testing purposes’ and this statement is from the homepage of Selenium.”
Because it isn’t designed for scraping, the learning curve of Selenium is steeper than that of purpose-made web scrapers. Inexperienced users may have to spend a while learning the program well enough to get it to do what they want, while dedicated web scrapers will function that way out of the box.
There are also speed issues when using Selenium to scrape data. It’s much slower than the other tools out there made for web scraping, which makes it a poor choice to use for a large-scale or even medium-scale scraping operation.
Say you manage a large business and want to improve your SEO. You decide to use web scraping to locate keywords from the top results in Google search. Sites large enough to make the top ten in a Google search are likely to have a lot of data to comb through. If you’re using Selenium, it’s going to take longer to get results.
So while there are people who use Selenium to scrape data, and who advocate for that use case, we don’t believe it’s the best option. It’s much less of a hassle to use a pre-built web scraping bot if you can.
What Selenium Can Be Used For
Instead of data scraping, Selenium is best suited to its original purpose: testing web pages. If you’re a developer planning to test out websites across multiple browsers, Selenium makes sense.
If you’re developing a page or app and want to scrape the data from it and test it at the same time, Selenium can be a good choice. This allows you to monitor the code for any mistakes during development and test functionality at the same time. It’s a small-scale use case where Selenium works well.
Selenium can also be useful for people just learning the basics of web scraping. It displays everything in real time, providing visual feedback for the user to help reinforce the concepts they’re learning.
That said, if you’re want to get started quickly and execute large-scale data scraping projects, Selenium will be more of a hindrance than a help.
What To Use Instead of Selenium
If you need results quickly, and have minimal coding knowledge, a pre-built scraping tool is the way to go. Scraping Robot has an application programming interface (API) that can pull the HTML code from any website URL you enter, letting you scrape a site in just a few seconds. Once the scraping is complete, you can download the output.
A pre-built scraper will let you get started right away, allowing you to experiment with different parameters and requests. You can test out different request headers, residential or data center proxies, and so on. A web scraping API doesn’t require you to enter multiple points of data manually — you just enter one site URL and it returns the code.
You can program a pre-built scraper to retrieve data from a page as seldom or as often as you need. A word of warning, though: don’t blast a page with dozens of requests a second. Programming your scraper to send requests at random intervals seconds or minutes apart will help prevent you from being blocked.
Pre-built scrapers also include a high-quality set of proxies you can use when scraping. Proxies are an integral part of any web scraper’s toolkit, as they mask your location and identity by mimicking normal human browsing when sending requests for data.
Pre-built tools usually have a customer service team behind them. That means that if you’ve got a need their scraper doesn’t currently satisfy, you can contact their team to work it out. Chances are they’ll be able to build something into the program so it can meet your needs. A team of developers irons out the kinks so you don’t have to.
You also won’t need to worry about anti-bot mechanisms with a good pre-built scraper. The team behind it will have planned for anti-bot measures and built in workarounds.
And lastly, the interface of a pre-built tool is usually straightforward and easy to use. A good web scraping tool will be intuitive and fast, allowing you to get up and running quickly without a ton of time spent learning the ropes.
Smarter Web Scraping
You should now have a better idea of why people use Selenium to scrape data, why it might not be the best tool for your needs, and what alternatives you can use instead.
A quick search will tell you there are multiple tools you can use to scrape data. If you’ve got the coding knowledge you can even build one yourself.
Scraping Robot makes pre-built APIs for a variety of use cases, from social media data to SERP pages and beyond. They’re all easy to use and backed by a 24/7 support team. Visit the site to learn more about the multiple scraping tools on offer, and contact us if you need a custom solution. Our developers can work with you to get something built that meets your needs.
The information contained within this article, including information posted by official staff, guest-submitted material, message board postings, or other third-party material is presented solely for the purposes of education and furtherance of the knowledge of the reader. All trademarks used in this publication are hereby acknowledged as the property of their respective owners.
Isaac has been writing for and about the tech industry since 2014 and has no plans to stop anytime soon. He now edits, and occasionally writes for, the Scraping Robot blog.