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What is the Difference Between Selenium 3 And Selenium 4?

Pravin Gamit
Pravin Gamit
  • May 29, 2024
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    7 min read
What is the Difference Between Selenium 3 And Selenium 4?
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Selenium has advanced web automation testing significantly, with notable growth seen in the transition from Selenium 3 to Selenium 4. These improvements play a pivotal role for individuals involved in testing and software development seeking to enhance their automated testing functionalities.  Selenium is a widely used tool by many automation testing companies that offer many automation testing services

What is Selenium Automation Testing?

Selenium is a popular tool used for making web tests automatic across different platforms and browsers.. This includes creating scripts that mimic the actions users take on web browsers, like clicking buttons, entering text, and checking for accuracy. By automating these tasks, testers can effectively verify the functionality and speed of web applications on various browsers and platforms. 

Additionally, Selenium is essential in the testing industry because it is open-source. It's additional dynamic features of selenium testing make the QA process faster and result-driven.  This approach reduces the requirement for manual labor, speeds up testing processes, and improves the overall performance of web applications.

The Architecture of Selenium 3

Selenium 3's structure was constructed based on the JSON Wire Protocol, acting as the communication link connecting Selenium client libraries and browser drivers. Although strong for its era, this design showed restrictions in both compatibility and performance. With the progression of web technologies, Selenium 3 encountered obstacles in staying up to date with the changing environment of contemporary browsers and web applications.

Architecture of Selenium 3

The Architecture of Selenium 4

Selenium 4 brings in a redesigned structure, incorporating the enhanced W3C WebDriver protocol. This marks a major advancement in Selenium's structure, in line with current web norms and top techniques. Switching to the W3C protocol improves compatibility with modern browsers and boosts debugging features. The restructured architecture of Selenium 4 demonstrates a dedication to meeting the changing requirements of hire automation testers, establishing it as the top option for web automation testing. 

Architecture of Selenium 4

Key Difference between selenium 3 and selenium 4

Having a clear understanding of the difference between Selenium 3 and Selenium 4 is essential in order to fully utilize the capabilities of Selenium 4.

ChromeDriver Handling

  • Selenium 3
    • Compatibility issues frequently occurred with newer Chrome versions.
    • Required manual updates of the ChromeDriver to ensure compatibility, leading to disruptions in testing.
    • When initiating the use of ChromeDriver, it often required explicitly specifying the driver's path:
from selenium import webdriver
from import Service

service = Service('/path/to/chromedriver')
driver = webdriver.Chrome(service=service)
  • Selenium 4
    • Provides smooth integration with the most recent Chrome releases.
    • Simplifies ChromeDriver handling, reducing the need for manual updates and improving compatibility.
    • Ensures continuous testing by seamlessly incorporating the latest Chrome versions.

Native Support for DevTools API

  • Selenium 3
    • Does not have built-in support for the DevTools API.
    • Testers need to rely on external libraries or tools to access browser internals.
  • Selenium 4
    • Introduces native support for the Chrome DevTools Protocol (CDP).
    • Allows testers to directly interact with browser features such as network conditions, performance testing metrics, and more.
    • Enhances debugging capabilities and allows for more in-depth browser automation.

Example Snippets Using Selenium 4 with CDP:

  • Throttle Network Conditions
    Creates a slow 3G network environment, helpful for assessing the performance of your application under various network speeds.
driver.execute_cdp_cmd('Network.enable', {})
driver.execute_cdp_cmd('Network.emulateNetworkConditions', {
    'offline': False,
    'latency': 200,  # ms
    'downloadThroughput': 780 * 1024 / 8,  # 780 kbps
    'uploadThroughput': 330 * 1024 / 8,  # 330 kbps
  • Get Performance Metrics
    Gathers different performance indicators from the browser, including load times and script execution times, to pinpoint performance bottlenecks.
performance_metrics = driver.execute_cdp_cmd('Performance.getMetrics', {})
print("Performance Metrics:", performance_metrics)
  • Capture Console Logs
    Allows for capturing browser console logs, which is useful for troubleshooting problems on the client-side.
driver.execute_cdp_cmd('Log.enable', {})
logs = driver.get_log("browser")
for log in logs:

Enhanced Selenium Grid

  • Selenium 3
    • Traditional Grid architecture.
    • Setting up and managing Grid nodes and hubs can be complex.
    • Limited support for scalability and parallel test execution.
  • Selenium 4
    • Revamped Selenium Grid with improved architecture.
    • Easier setup and management of nodes and hubs.
    • Better support for parallel test execution, aiding in faster test completion.
    • Enhanced scalability and resource management.

Relative Locators

  • Selenium 3
    • Relies on traditional locators like id, name, className, tagName, linkText, partialLinkText, CSS Selector, and XPATH.
    • Element identification may require complex and lengthy locators.
  • Selenium 4
    • Introduces relative locators (previously known as "Friendly Locators").
    • Enables locating elements based on their position relative to other elements (e.g., toLeftOf, toRightOf, above, below, near).
    • Simplifies element identification and makes test scripts more readable and maintainable.

Let see the examples:

  • Right Of
element_to_right = driver.find_element(locate_with(By.TAG_NAME, "button").to_right_of(reference_element))
  • Left Of
element_to_left = driver.find_element(locate_with(By.TAG_NAME, "button").to_left_of(reference_element))
  • Above Of
element_above = driver.find_element(locate_with(By.TAG_NAME, "input").above(reference_element))
  • Below Of
element_below = driver.find_element(locate_with(By.TAG_NAME, "input").below(reference_element))
  • Near Of
element_near = driver.find_element(locate_with(By.TAG_NAME, "input").near(reference_element))

Selenium IDE

  • Selenium 3
    • Selenium IDE was deprecated and then reintroduced with basic functionalities.
    • Limited in terms of advanced features and usability.
  • Selenium 4
    • Updated Selenium IDE with a more robust and user-friendly interface.
    • Enhanced capabilities for recording, editing, and debugging test scripts.
    • Features intelligent element selection, auto-completion, and integrated debugging tools.
    • Improves productivity and ease of use for testers at all levels.

W2C WebDriver Standard

  • Selenium 3
    • Partial implementation of the W3C WebDriver standard.
    • Some inconsistencies between browser drivers due to varying levels of compliance.
  • Selenium 4
    • Full compliance with the W3C WebDriver standard.
    • Ensures a more consistent and reliable behavior across different browser drivers.
    • Facilitates better compatibility and stability in test automation.

Improved Documentation and Support

  • Selenium 3
    • Documentation was sometimes seen as lacking in depth and clarity.
    • Testers often had to rely on community forums for troubleshooting.
  • Selenium 4
    • Offers improved and more comprehensive documentation.
    • Includes detailed guides and examples, making it easier for users to understand and implement features.
    • Better support from the Selenium community and maintainers.

Enhanced Window and Tab Management

  • Selenium 3
    • Basic support for managing browser windows and tabs.
    • Switching between windows and tabs often required workarounds.
  • Selenium 4
    • Provides more robust APIs for managing browser windows and tabs.
    • Easier to switch between windows and tabs with the new Window and WindowType classes.
    • Improved handling of new windows and tabs in test scripts.

Better Browser Driver Management

  • Selenium 3
    • Users often had to manually download and manage browser drivers.
  • Selenium 4
    • Integration with WebDriverManager, simplifying the process of downloading and managing browser drivers.
    • Automates the setup and management of browser drivers, reducing configuration effort.
from selenium import webdriver
from import ChromeDriverManager

# Initialize WebDriver
driver = webdriver.Chrome(ChromeDriverManager().install())

New Feature in WebDriver

  • Selenium 3
    • Limited to existing WebDriver functionalities.
  • Selenium 4
    • Adds new WebDriver features like executeAsyncScript for better handling of asynchronous operations.
    • Improved support for handling modern web applications with new commands and functionalities.

Table content compared selenium 3 VS selenium 4

Contrasting Selenium 3 with Selenium 4 reveals advancements and enhancements in automated testing features.

Feature Selenium 3 Selenium 4
WebDriver Based on JSON Wire Protocol Supports W3C WebDriver protocol
Compatibility Potential compatibility issues with newer browser versions Enhanced compatibility with modern browsers
Debugging Limited debugging capabilities Improved debugging tools and APIs
Performance Stable but may encounter performance issues with complex web applications Enhanced performance and stability


To conclude, the shift from Selenium 3 to Selenium 4 represents a major progression in web automation testing. Testers and developers can take advantage of Selenium 4's enhanced structure, upgraded compatibility, and innovative features. Utilizing Selenium 4 enables teams to make testing processes more efficient, improve software quality, and meet business goals more successfully.

It is essential to stay up-to-date with the latest QA software testing services and techniques to make testing process more efficient and effective. As web applications grow and get complex, the testing tools also need to be improve. Alphabin always adopted the latest technologies and stay up-to-date in appling testing methodologies.

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Frequently Asked Questions

What are the key differences between Selenium 3 and Selenium 4?
FAQ Arrow

Selenium 4 brings forth notable enhancements in its architecture, functionalities, and efficiency in contrast to Selenium 3. A key distinction lies in the fundamental protocol employed for communication. Whereas Selenium 3 employed the JSON Wire Protocol, Selenium 4 has transitioned to utilizing the W3C WebDriver protocol, which is considered more contemporary and in accordance with prevailing web norms. Moreover, Selenium 4 presents upgraded debugging capabilities and heightened browser compatibility.

How does the architecture change from Selenium 3 to Selenium 4 impact testing workflows?
FAQ Arrow

The shift from Selenium 3 to Selenium 4 results in various changes in architecture that have a direct effect on testing processes. Testers can anticipate increased compatibility with modern browsers and enhanced stability thanks to Selenium 4's integration of the W3C WebDriver protocol. This guarantees that test scripts run more smoothly on various browser versions and platforms. Additionally, the improved debugging features in Selenium 4 help testers address problems more efficiently, resulting in quicker bug fixes and enhanced test scope.

Is it worth upgrading from Selenium 3 to Selenium 4?
FAQ Arrow

Indeed, companies interested in benefiting from the latest advancements in automated testing should think about transitioning from Selenium 3 to Selenium 4. Selenium 4 provides a range of advantages, such as improved browser compatibility, enhanced debugging capabilities, and integrated backing for contemporary web development tools. Furthermore, using the W3C WebDriver protocol assures better compliance with industry standards, making your automation system more resistant to obsolescence. Although updating current test suites may require some initial effort, the long-term benefits are worthwhile.

Will my existing Selenium 3 test scripts be compatible with Selenium 4?
FAQ Arrow

Generally, current Selenium 3 test scripts should function with Selenium 4 with very minor changes. Nonetheless, comprehensive testing is recommended to ensure compatibility, especially if your test suite relies on specific features or functions that may have been altered in Selenium 4. Furthermore, using Selenium 4's increased debugging features can help you easily identify and resolve compatibility issues.

About the author

Pravin Gamit

Pravin Gamit

Pravin Gamit, as a Sr.QA Automation Engineer at Alphabin, I specialize in APIs and user interfaces to create strong testing systems that make sure software works great.

I'm all about making things better with automated testing.

More about the author
Join 1,241 readers who are obsessed with testing.
Consult the author or an expert on this topic.
Join 1,241 readers who are obsessed with testing.
Consult the author or an expert on this topic.