Selenium WebDriver supports multiple browsers. It is mainly used for automation testing of web applications. Learning about what is Selenium WebDriver is required to understand web development concepts. This involves learning about the request-response cycle and execution flow. 

Selenium WebDriver is a collection of APIs. It provides a programming interface for developers and testers to write scripts in various languages. Test scripts automate web browser actions and retrieve information from web pages.

Selenium 4 WebDriver is the latest version being used. However, knowing about Selenium 3 Webdriver is essential. In this blog, let us know what is Selenium WebDriver and the working mechanism of the architecture. 

What is Selenium WebDriver? – An Overview

It is a popular tool for automating web browser interactions. You can create scripts for automation testing and other browser tasks. 

  • Cross-Browser Testing: Selenium WebDriver supports multiple browsers. You can write a script once and run it on different browsers. It can easily support and integrate with cloud-based platforms like LambdaTest. LambdaTest is an AI-driven test orchestration and execution platform. It supports manual and automated testing on a remote test lab featuring over 3000 real devices, browsers, and OS combinations. 

Key features: 

  • Enables integration with automation testing tools such as Selenium, Playwright, Cypress, Puppeteer, Taiko, Appium, Espresso, XCUITest, and others.
  • Offers visual regression testing powered by AI to automatically compare various browsers and devices, detecting visual differences.
  • Enables live-interactive and automated screenshot testing in multiple environments.
  • Accelerates test automation using HyperExecute, a fast end-to-end test orchestration cloud.
  • Allows for geolocation testing for web and mobile apps in over 53 geographic locations.
  • Connects to CI/CD tools, project management platforms, and codeless automation solutions.
  • Provides well-known QA certifications to confirm your expertise in QA testing.
  • Automation Scripts: You can automate repetitive tasks using Selenium WebDriver. This reduces the chance of human error.
  • Real User Simulation: Selenium WebDriver interacts with web pages just like a real user. It clicks, types, and navigates through web pages. 
  • Supports Multiple Languages: You can write Selenium WebDriver scripts in several programming languages. 
  • Integration: Selenium WebDriver integrates well with other testing frameworks. This makes it easier to manage your test cases and generate reports. 

The Architecture of Selenium 3 WebDriver

The architecture contains several key components to automate web browser interactions. Below are the key components of the architecture: 

Browser Drivers

Browser drivers act as a bridge between Selenium WebDriver and the web browser. They translate commands from Selenium into actions on the browser.

  • Compatibility: Browser drivers are designed to be compatible with specific web browsers. This ensures that commands are executed accurately within the browser environment.
  • Automation Control: They allow Selenium WebDriver to control browser actions. This includes clicking buttons, entering text, and navigating between pages.
  • Direct Communication: Browser drivers communicate directly with the browser. This direct communication helps achieve precise automation results.
  • Different Browsers: There are specific drivers for different browsers like Chrome, Firefox, and Safari browser online. Each driver ensures that the browser’s unique features are supported.

JSON Wire Protocol

This protocol is a transport mechanism used by Selenium WebDriver. It makes the communication between the client and the server.

  • Standardized Communication: This protocol standardizes the way Selenium commands are sent and received. It ensures consistent communication across different systems.
  • Data Transmission: JSON Wire Protocol transmits data in a structured format. This helps in accurately conveying commands and responses between the client and server.
  • RESTful API: It uses RESTful API principles for communication. This makes it easier to understand and implement within the WebDriver architecture.
  • Command Execution: The protocol specifies how each command should be executed. This clarity helps in precise automation and reduces errors.

Selenium Client Library

The Selenium Client Library is a collection of language-specific bindings. These bindings allow you to write Selenium scripts in different programming languages.

  • Language Support: The client library supports multiple programming languages like Java and Python.
  • Ease of Use: The user-friendly methods and functions simplify the process of writing automation scripts.
  • API Access: The client library offers access to the WebDriver API. This access enables you to interact with web elements and perform various actions.
  • Community Support The client library is widely used and supported by a large community. This ensures regular updates and the availability of resources.

Selenium Server

Selenium Server acts as a middle layer between the Selenium Client and the browser. It is essential for running tests on remote machines.

  • Remote Execution: Selenium Server enables remote execution of test scripts. This allows you to run tests on different machines or in cloud environments.
  • Grid Configuration: It supports Selenium Grid, which allows parallel execution of tests. This helps in speeding up the testing process by running multiple tests simultaneously.
  • Central Control: Selenium Server provides central control over the testing environment. This centralization simplifies the management of test configurations and resources.
  • Scalability: It allows for scalable test execution. You can add more machines to the grid to handle larger test suites effectively.

The Architecture of Selenium 4 WebDriver 

The only difference between Selenium 3 WebDriver and 4 is that Selenium 3 WebDriver doesn’t support direct connections to the client libraries and browser drivers. Selenium 4 WebDriver has a modern architecture designed to improve browser automation. 

Here are the components: 

  • WebDriver BiDi: WebDriver BiDi enables bidirectional communication between the client and the browser. It gives immediate feedback and more advanced automation capabilities.
  • W3C Standard Compliance: It is fully compliant with the W3C WebDriver standard. This ensures compatibility and consistency across different browsers.
  • Enhanced Selenium Grid: The new Selenium Grid offers better scalability and flexibility. It supports distributed test execution and tests to run across multiple machines simultaneously.
  • Relative Locators: Relative locators find elements based on their position. This simplifies element identification and enhances the readability of test scripts.
  • New Window and Tab Management: WebDriver 4 introduces improved management of windows and tabs. This makes it easier to test complex applications.
  • Improved Performance: The architecture focuses on performance improvements, resulting in faster execution and better resource management. Commands are optimized for efficiency, reducing overhead.

What is Selenium WebDriver’s Architecture Working Mechanism? – A Comprehensive Guide

Selenium WebDriver automates web browser interactions by following a structured process. It uses various components to execute commands and control browser actions.

Script Creation

You write a test script with commands for browser actions, such as navigating to a website and clicking elements.

  • Code Writing: Write the test script in your preferred programming language. Include steps for interacting with web elements.
  • Element Identification: Use locators to identify web elements. Common locators include ID, name, and CSS selectors.
  • Action Commands: Include commands to perform actions like clicking buttons, entering text, and verifying results.
  • Assertions: Use assertions to validate test outcomes. They check if the web application behaves as expected.

Command Execution

The Selenium Client Library sends commands from your script to the WebDriver, which translates them into browser actions.

  • API Interaction: The client library interacts with the WebDriver API, providing methods to control browser behavior.
  • Command Translation: WebDriver translates high-level commands into browser-specific instructions for accurate execution.
  • Request Sending: The WebDriver sends requests to the browser driver and instructs the browser on actions to perform.
  • Real-Time Execution: The browser driver executes commands in real time. You can see the actions performed in the browser.

Browser Drivers

Browser drivers act as intermediaries between WebDriver and the browser, ensuring accurate command execution.

  • Driver Launching: The browser driver launches the specified browser and establishes a session for communication.
  • Direct Control: The driver takes direct control of the browser, performing actions like clicking, typing, and navigating.
  • Session Management: The driver manages the browser session, maintaining the browser state throughout the test.
  • Result Reporting: The driver reports the results of executed commands back to WebDriver, helping track action success or failure.

JSON Wire Protocol

The JSON Wire Protocol is used for communication between WebDriver and browser drivers, ensuring correct command transmission.

  • Request Formatting: Commands are formatted as JSON objects for clear communication.
  • Data Transmission: The protocol transmits data between WebDriver and the browser driver, including command instructions and responses.
  • Error Handling: The protocol handles communication errors, reporting issues back to WebDriver.
  • Standardization: The use of a standard protocol ensures compatibility, allowing different components to work together seamlessly.

Browser Interaction

The browser driver interacts with the web browser to perform actions specified in the test script.

  • Element Interaction: The driver interacts with web elements as specified, including clicking, typing, and selecting options.
  • Navigation: The driver navigates to URLs specified in the test script, handling page loads and redirects.
  • State Management: The driver manages the browser state, handling cookies, sessions, and other state-related aspects.
  • Script Execution: The driver executes JavaScript within the browser, allowing for complex interactions and validations.

Test Validation

The final step involves validating the test results. Assertions in the script help verify if the test passed or failed.

  • Result Checking: Assertions check the outcome of actions performed by the browser, verifying if expected results are achieved.
  • Error Reporting: Any errors encountered during the test are reported. It identifies issues in the web application.
  • Test Logging: Logs are generated for each test run. This provides detailed information about the test execution.
  • Result Analysis: Analyze results to determine test success, helping improve test scripts.

Integration

Selenium WebDriver integrates easily with cloud-based tools and frameworks. This integration enhances the overall testing process.

  • CI/CD Pipelines: WebDriver integrates into CI/CD pipelines. This provides continuous testing during development.
  • Reporting Tools: Integration with reporting tools provides detailed test reports, aiding in result analysis and issue identification.
  • Test Management: WebDriver integrates with test management tools, simplifying test case management and organization.
  • Version Control: Integration with version control systems ensures proper test script management, maintaining test suite integrity.

Conclusion

Thus, knowing about what is Selenium Webdriver and its architecture is essential for testers and developers to use it to the fullest. You can easily understand the concepts and extend your innovations by introducing new testing mechanisms in your organizations. You need to learn what is selenium WebDriver to conduct the testing process accurately. 

Selenium 4 WebDriver is now being used in the market. However, directly using Selenium 4 WebDriver rather than not learning about Selenium 3 WebDriver is not recommended. The new features provide more reliable and easy automation. Selenium WebDriver is an essential tool for developers and testers. They can aim for high-quality web automation.