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Comparison between Selenium 3 and Selenium 4

Group of web developers working in an office.

In this blog, I will evaluate the Selenium 3 and Selenium 4 architectures before highlighting a few Selenium 4 benefits. I will also go over the new features added to Selenium IDE, Selenium WebDriver, and Selenium Grid in Selenium 4.

The fundamental cause for Selenium’s upgrading is the W3C WebDriver Protocol, which is the most significant difference between Selenium 3 and Selenium 4. The Worldwide Online Consortium, or W3C, is a global organization that creates web standards. The behavior of a web browser is managed via the WebDriver Protocol.


The blog is broken out as follows:

  • Architecture for Selenium 3 vs Selenium 4 
  • Advantages of Selenium 4
  • New Features in Selenium 4
  • Comparison of Selenium 3 and Selenium 4


Selenium 3 Architecture

The information must be sent over HTTP from the client to the server using the JSON Wire Protocol. The abbreviation HTTP stands for Hyper Text Transfer Protocol. The Selenium Client and WebDriver Language Bindings components both send a Selenium request. The JSON Wire Protocol Over HTTP subsequently receives the request, which is then secured by the Browser Driver.

The request command is then sent to a web browser, where automation is performed. A response is sent back to the Browser Driver, JSON Wire Protocol, and Selenium Client & WebDriver Language Bindings once the automation is finished.

Selenium 4 Architecture

Selenium 4 has a direct client-server connection, as opposed to Selenium 3. While Browser Drivers are the server, the client still consists of two components: the Selenium Client and WebDriver Language Bindings.

  • The Selenium Client issues a command-performance request.
  • A code library called the WebDriver Language Bindings is intended to power actions.

The built-in automation support of each Web browser is utilized by WebDriver to operate the Browser Drivers and Web Browsers. The Chrome browser is managed by a Browser Driver like ChromeDriver.

The drivers have changed in Selenium 4. While RemoteWebDriver is ChromiumDriver’s parent, ChromeDriver and EdgeDriver extend it.

Selenium 4 Advantages

Selenium 4 acquired at least three benefits in succession as a result of the upgrade. The benefits are:

  • Stability
  • Standards
  • Updated Actions API

Because of the standards, our Test Scripts function more consistently across all browsers. There is a standard used by all browser vendors. Since Selenium 4 is W3C WebDriver compatible, the request’s encoding and decoding are no longer necessary.

Another benefit of backward compatibility is stability. The Selenium Server and the Java Bindings both offer a way to use the outdated JSON Wire Protocol. The Actions API for keyboard and mouse events has been updated. It allows the ability to perform multiple actions simultaneously, such as pushing two keys.

Selenium 4 New Features

Selenium IDE, Selenium WebDriver, and Selenium Grid are among the new features of Selenium 4.

  • Selenium IDE gives us the ability to record, replay, edit, and debug our tests.
  • Selenium WebDriver is an API for automating an Application Under Test that runs our test by driving a browser (AUT).
  • Selenium Grid runs our test on several machines, operating systems, and browsers.

Backup Element Selectors and Control Flows were gained by Selenium IDE. For each element, the Backup Element Selectors keep track of numerous locators. In Selenium IDE, Control Flows help with statement execution. Conditionals and loops make up the control flows.


  • if
  • else-if
  • else
  • end


  • do-repeat if
  • while
  • times
  • forEach

Selenium 3:

The Chrome driver in Selenium 3 connects directly to the remote Web driver.

JSON Wire protocol was the primary means of communication between the test code and the browser in Selenium 3.

To execute automation testing on the grid, testers had to always start the hub and node jars, which was a challenging task in Selenium 3.

Selenium 4:

Chrome driver class extends to the chromium driver in Selenium 4, which provides several built-in ways to access the development tool.

Due to its adherence to the w3c, Selenium 4 effectively uses the web driver e3c protocol.

The hub and note jars do not need to be started every time an automation test is run using Selenium 4.

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Mangesh Sonwane

Mangesh Sonwane is an Associate Technical Consultant at Perficient in Nagpur GDC. He has an experience of 1+ years in Drupal and AEM. Apart from this passionate about learning new changes and expanding his knowledge in Automation. He is very committed to his work and is always ready to face any challenging projects.

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