Performance Comparison – Selenium 3 And Selenium 4

When it comes to test automation, Selenium has always stayed to be the first name to hit the mind of the testing community. From being an open-source community-based platform to offering the massive ease of use, Selenium is the primary choice for most organizations looking for test automation solutions.  

And therefore, catering to the extensive needs of the clients, Selenium always works on introducing new updates and releases that could meet the needs of the community. To enable the QA community to enjoy the best of test automation, Selenium introduced its very recent version 4.  

Officially released on October 2021, Selenium 4 brought so many new upgrades which include the elimination of features like JSON wire protocol as well as modification of Selenium architecture. Besides, Selenium focused on various standardizations and stabilizations to complement the automation process.  

With that being said, let us quickly jump on learning what makes Selenium 4 a better tool compared to Selenium version 3, in terms of performance, features, and other benchmarks.  

Architectural Upgrades On Selenium 4  

When it comes to the architectural upgrades made to Selenium 4, one of the most significant changes introduced was the elimination of JSON Wire Protocol. More importantly, it was the one of the most crucial reasons that triggered the Selenium 4 upgrade as the protocol allowed users on Selenium 3 to communicate with the web browser.  

With Selenium 4, a direct communication between client and server could be established using the W3C protocol, which offers a lot of benefits when compared to older versions of web driver. 

Apart from this, Selenium 4 got native support removed for the Opera driver which means testers now need to use the Chromium based Chrome as the opera browser.  

Above all, the replacement of JSON Wire Protocol with W3C enabled users to resist the hassle of encoding or decoding requests, delivering greater stability and consistency.  

What Selenium 3 features got subtracted with Selenium 4 Release?  

• Find Element 

To add more stability, the ‘By’ class can be annotated rather than the use of utility methods to locate elements in the ‘FindBy’ interface as they were limited to internal use only.  

• Desired Capabilities 

To allow users define specific options for drivers, the desired capabilities were replaced with Options to simplify defining of test environments in Selenium Grid.  

• Actions Class 

With action class, users could simulate gestures like double click, click & hold, etc. Moreover, Selenium 4 even called for various new additions to the class along with so many deprecated methods. These include: 

• Browser type  
• Browser Interface 
• Firefox Legacy 
• Merging Capabilities 
• Timeout Parameters 
• Wait Parameters 

What Is New In Selenium 4?  

The introduction of Selenium 4 brought so many remarkable innovations. From the provision of taking element screenshots to resolving several other pain points, Selenium update showed some standardized libraries to fasten the operations.   

Taking Screenshot Of The Elements 

Taking screenshots was one of the most complicated actions to perform on Selenium 3. It required the testers to take screenshot of the screen and then crop it as per the coordinates of the desired element. However, the release of Selenium 4 simplified the entire task allowing the tester to achieve the same with a few lines of code. The convenience offered allowed testers to yield dramatic performance improvement as it cuts off all the additional effort.   

Multiple Tabs 

Another significant advantage that testers get to experience with Selenium 4 was struggle to open a new window or a tab. Earlier, it required tester to run a set of JavaScript commands or a sequence of shortcut keys on screen to execute the same. But, if you are using Selenium 4, you can do the same by simply giving a switch tab command to the driver.  

Relative Locators 

To locate elements was another crucial task that testers had to deal with when performing UI testing. With relative locators, testers no longer need to work through ‘findElement’ method as Selenium 4 simplifies element location by using an element which is already located. Actually, the current version works on a code block that finds search bar in google and sends keys of the same to the Relative Locator. Furthermore, it checks for the ‘input’ made to the search bar to find any elements. 

Connection Conditions 

Selenium 4 has also introduced various connection features such as latency, going offline, setting download, or upload throughput.  

Full Page Screenshot Using Firefox 

Selenium 4 was introduced with a more simplified way to take screenshots unlike its older versions. In Selenium 3 or older versions, testers could only take the screenshot of the current view and not the whole page. However, Selenium 4 allows testers to take screenshot of the entire page for all the infinite scrolls. 

Improved Speed & Efficiency 

As Selenium 4 offered replacement of W3C with JSON Wire Protocol, testers could now work on test cases that could directly communicate with the browser. Though there is not much visible difference in terms of speed, Selenium 4 makes the overall process appear very fast, efficient, and convenient. However, the use of same protocol by the Web Driver and web browser makes the overall process very consistent cutting off all the flakiness.  

Chrome Dev Tools 

With the newer releases of the Selenium, there have been some significant changes made to the API. Earlier, Chrome driver in selenium 3 only extended to remote web driver class. On the other hand, Selenium 4 extended the chrome driver class to chromium driver which contains some predefined methods to access dev tools.  

Selenium 3 or Selenium 4: Which Is Better? 

When it comes to making the final call between selenium 3 and selenium 4, it must be understood that both are the different versions of a similar tool and ultimately, they both belong to the same family.  

As far as it is associated with difference of the performance, testers and QA using Selenium understand that both these versions are built different from each other. It is just that Selenium 4 is designed to meet the latest objectives and overcome the pain points from the older versions. These include the WebDriverManager class as well as relative locators that simplifies the entire test process with easy web element location and skipping the hassle of downloading the executable, ultimately improving the entire test process and performance.