The first question that comes to mind when you see the word Selenium is: What is Selenium, and what are its uses? 
Therefore, through this blog, we will try to cover all aspects of Selenium. After reading the whole blog, you will be able to know the fact that what lies at the core of your next job role if you are enthusiastic to learn the Automation testing method using Selenium. 

Right now, it has taken over the traditional quality assurance methodologies in IT industries worldwide and has set a benchmark in terms of Quality assurance because it is fully automated, and one of the most demanded expertise that is required in the industry is “Selenium Certification”. 

What is Selenium? 

For starters, Selenium is an open-source tool available to automate the required tests to be carried out on the existing web-based browsers. (In simpler words, it tests the web applications by using any web-based browsers like Google Chrome, Mozilla Firefox, Opera Browser, Internet Explorer, MS Edge, etc.) 

Now, before you start exploring your imagination, let me clear something very important about Selenium, i.e., you can only test the web applications using Selenium, and it is not used to test either the software (desktop applications) or any mobile-based applications. This can also be considered as one of the drawbacks of Selenium that we will discuss later. 

The good thing is that you can automate the testing of software and mobile applications by using other available tools like: RFT from IBM, QPT by HP, Appium, etc. 

This blog is also focused on the testing and quality analysis of the dynamic web applications and the reasons that make Selenium the best solution to achieve/fulfill this purpose. 

Well, first things first. We discussed above that Selenium is open source, which means that you don’t need to pay for the licensing in order to use this tool and this is one of the main and major reasons for the popularity of this trend in Automation Testing. 

Benefits and Advantages of the Use of Selenium 

The following are the benefits and advantages of using Selenium: 

• The Quality Analyst can use any of these programming platforms to write the test scripts: C#, PHP, .NET, Java, Python, Ruby & Perl. 

• You can carry out the test on not just one operating system, but also on Windows, Mac, or Linux as well. 

• You can use different browsers to perform the tasks: Mozilla Firefox, Google Chrome, Internet Explorer, Opera, and Safari. 

• The tools like TestNG and Junit can be integrated with Selenium to generate the reports and manage the test cases. 

• Maven, Jenkins & Docker can also be integrated with Selenium to perform continuous Testing. 

By now, you must be thinking if Selenium is so perfect that there are no limitations or disadvantages, or shortcomings with this approach. So here is the answer to your confusion. 

Drawbacks with Selenium 

Below are the drawbacks of Selenium: 

• The first and foremost in this category is the fact that you can use Selenium to test the web applications only, and not to test the desktop applications or any other software. 

• At present, there is no dedicated product support for the users of Selenium. They have to rely upon the online user communities to share the issues with them or to find solutions to the same. 

• If you want to test an image via Selenium, you will be disappointed. In order to achieve image-based testing, you will first have to integrate Selenium with Sikuli. 

• Selenium is not equipped with a native reporting facility, but if that is required necessarily then you can integrate Selenium with TestNG or JUnit to solve this issue. 

Before we head further, I think we should first know why Selenium was required at the first place or why Selenium became what Selenium is today. So, join the journey in the following order: 

1. The requirement for Software Testing 

2. Manual testing limitations 

3. Is automation testing better than manual testing? 

4. Selenium v/s other available testing tools. 

5. Selenium suite of tools 

Also, read: 11 Questions on QA and testing to Ask Your App Development Partner

Requirement for Software Testing 

Software testing is where everything sums up in the end. We are living in a world where our lives are totally dependent on the machines, one way or another, and the interesting part is that the overall behavior of these machines is controlled and manipulated by the software that is empowering these machines or tools. 

This is where Software testing comes into the picture, which verifies if the machines are acting exactly as we want them to act and also verifies if the machine is working properly each and every time and everywhere as well. 

No matter what you do as a service provider, your business growth in the end will be controlled by the success rate of your software application and web application because the majority of today’s businesses depend completely on the internet. 

Let me give you an example. The big e-commerce companies like Flipkart or be it Myntra, they depend on the traffic of users or their customers on their web sites and also the traffic of the same people on their mobile based applications regarding the same purpose. 

Now imagine if something unthinkable happens, like prices of all products are zero, and it happened because of a small bug/defect in such a part of the code that is not very easy to read, then how will the situation be rectified, and how will the same situation be prevented from the next time? 

The simplest answer is: By testing the code before the deployment, and that’s the requirement of testing the software as well. 

Now, let me clear something before we discuss anything further that there are two ways to accomplish software testing: Manually and via Automation. 

Selenium was designed as an automation tool to cover the areas that were not possible to cover with manual testing, so the next part of this blog will discuss the limitations of manual testing. 

Also, read: What is Smoke Testing? Its Role & Benefits | SQA

Manual Testing Limitations 

Manual testing refers to the process of testing the web applications by looking at and using the functions and features of a web application as an end-user, and then making sure that the application is useful and working as per the requirement. 

In this method, a QA tester conducts all the tests on the software/application by following the pre-defined sets of test cases and also maintains the records of all the success or failure rates of all these transactions. 

The challenges that a QA tester faces while manually verifying the recorded transactions can cause fatigue, boredom, unnecessary delay in work, mistakes, and errors due to the manual approach etc. 

That’s why these reasons resulted in the invention of Selenium we know today

Is Automation Testing better than Manual Testing? 

Automation testing is always a better choice than manual testing. The reason is pretty simple. This approach is faster, requires low investment in putting human resources for one single task, as compared to the manual approach, to execute the same test cases over and over again in bulk is way easier, it makes regression testing and functional testing more effective, and it is the most preferred approach to detect errors/bugs. 

Let me try to explain it a bit more with the help of an example. 

Suppose I am testing the login page of an application (web application) to verify if all the attempts to log in to check-in into the main page were successful. If I am testing it manually, then I will have to check the records by always going to the sign-in page and trying the same procedure over and over again. This can be really stressful and tiring. 

On the other hand, if I am doing the same thing via Selenium, then I will take some time to write a test script that will validate if all the login attempt transactions were successful or not. This will save me from the stress and fatigue of manually testing the login page. Selenium allows me to automate the testing process, making it more efficient and accurate. 

On top of that, all these tests can be performed in such a way that, before releasing the product for use, it can be confirmed that the product/web application supports different environments and web browsers as well. Now the next question arises that what else can we achieve using Selenium? 

Well, the answer is that you can not only automate your testing, but you can also automate the production/generation of result files, and you can schedule it as well for a particular time of any given day. 

This can be concluded easily that all these features of Selenium make a tester’s duties a whole lot easier than they once used to be till Selenium was not popular. 

Selenium v/s Other Available Testing Tools 

Now, let us have a look at where Selenium stands in the market. 

To do that, I have tried to compare the performance of Selenium with two other popular tools that are available in the market: QTP (From HP) and RFT (From IBM) in the table below. 

The above comparison must have given you a clear picture that why most people prefer Selenium over any other tool (For Quality Analysis).  Selenium has many components, and before choosing one, you should first know which one is perfect to fulfill your requirements.

Selenium Suite of Tools 

Selenium is made of different software tools, and each tool/component has a specific role.

• Selenium RC (Now deprecated) 

• Selenium IDE 

• Selenium Grid 

• Selenium WebDriver 

1. Selenium RC (Remote Control) 

I think I should first discuss the first tool of the Selenium project before talking about Selenium RC, and that tool was ‘Selenium Core’. But the same origin policy was the biggest issue with Selenium Core whenever cross-domain testing was required. 

To solve the issue of same-origin policy, the QA members had to install the local copies of both Selenium Core and the web server where the web application is supposed to be tested so that they could belong to the same domain. 

That was the reason for the existence of Selenium RC we know today, and it is certified by Paul Hammant, who was an engineer at ThoughtWork at that time. 

Selenium RC ruled out the issue by using a proxy HTTP server in such a way that the browser behaved as the Selenium Core, and the web application that was under testing was from the same domain, and this is the reason why RC is also known as a bi-component tool, namely: 

• Selenium RC Server- (It communicates via simple HTTP GET/ POST requests) 

• Selenium RC Client – (It is a library that contains the code of your programming language) 

The crown jewel of the project, Selenium, was Selenium RC because of two main reasons: a) Selenium RC was their first tool, and b) it had the ability to write test scripts in multiple programming platforms. 

But the issue with RC was that each transaction with its server was very time-consuming, which made it a slow tool as well. It has also been observed that in many cases it takes hours to accomplish just a single test case. 

RC is being deprecated since the release of Selenium V3 and has moved to the legacy package. However, you can still download and use RC, but you are not going to find support for it anywhere. 

But on the bright side, there is no point in using something that is outdated and is replaced with a much advanced and efficient tool which is Selenium WebDriver. 

Now, before I discuss WebDriver with you, let me talk about the other tools that collectively formed the Selenium V1.

2. Selenium IDE (Integrated Development Environment) 

Shinya Kastani from Japan gave his Selenium IDE prototype to Apache’s project based on Selenium in 2006. It was a Firefox-based plugin focused on faster creation of test cases. 

The vital feature of an IDE was the ability to record and playback, where test cases were created by recording the transactions between the user and the web browser. Later, these tests were available to be played back n number of times. 

One most important advantages with Selenium IDE is that you can export the tests that were created by using the plugin in multiple languages, like: Java, Python, and Ruby etc. 

The known issues with the IDE are: 

1. The plugin was available only for Mozilla Firefox. 

2. You can only record simple tests, and testing of dynamic web applications is not possible. 

3. You cannot script the test cases using programming logic. 

4. Data-driven testing is not supported by Selenium IDE. 

3. Selenium Grid 

Patrick Lightbody developed Selenium Grid and initially called it HostedQA. He used it with RC to accomplish the testing on remote machines. It was initially a part of Selenium V1. The most important feature of Grid was its ability to run multiple test scripts on multiple machines at the same time. 

The Hub-Node architecture is used to perform parallel execution. One machine is supposed to be acting as the Hub, and the other machine will be the Node, where the role of the Hub is to control different test scripts running on different browsers running on different Operating Systems. 

Parallel execution is achieved with the help of the Hub-Node architecture. One machine will be assumed to be acting as Hub and the other machine will be assumed to be acting as the Nodes. Hub controls the test scripts running on various browsers inside various operating systems. We can write the scripts in different programming languages that are being executed in different Nodes. 

Until this date, we have used Grid with both RC and WebDriver. However, it is not an easy task to maintain a grid with all the necessary operating systems and web browsers. 

To deal with this situation, various online platforms like “LambdaTest” are used. These platforms provide an online Selenium Grid that can be accessed to run and execute the automation script of Selenium. 

This makes it easier to test applications on a wide range of platforms without the need to physically set up and maintain a Selenium Grid. 

The Lambda Test acquires over 2000 browser-friendly environments that can be used to verify and run the required tests to achieve the goal of automating cross-browser testing. 

4. Selenium WebDriver 

In 2006, Simon Stewart founded Selenium WebDriver and was also the very first ever testing framework for cross-platform testing that was able to control the web browsers at the OS level. 

Unlike an IDE, it establishes a programming alliance to maintain and execute the test cases in such a way that the web elements on web pages were easy to identify, and also to perform actions on such elements is also easier. 

It can also be said about WebDriver that it is an upgrade to RC. One reason for this is that it is much faster than RC. Another reason is that it establishes direct calls to the web browsers, while RC cannot do this. 

RC needs an RC server to perform this task. WebDriver’s direct communication with the browser makes it a more efficient and effective tool for automated testing. 

We know that to run the applications, the browsers are equipped with their own drivers, for example: 

• Chrome Driver 

• Safari Driver 

• Internet Explorer Driver 

• Firefox Driver or Gecko Driver 

• Opera Driver and 

• HTM Unit Driver 

Merits of Selenium WebDriver 

Below are some advantages / merits of using Selenium WebDriver: 

• Able to perform cross-browser testing as it supports browsers like Firefox, Chrome, IE, etc. 

• Able to perform tests on multiple operating systems as Windows, Mac, Linux, Android, iOS, etc. 

• Compatible with 7 different programming platforms like JAVA, PHP, Ruby, Perl, Python, C#, and NET. 

• Resolved the issues with Selenium V1, like dialog barriers, pop-ups, file download, file upload, etc. 

Demerits of Selenium WebDriver 

Below are the major challenges that were encountered with Selenium WebDriver: 

• Generating detailed test reports is exhausting and mostly impossible. 

• You cannot test the images with Selenium WebDriver. 

Although these challenges can be handled but in order to do that, you need to integrate it with the other available frameworks like Skuli, which is used to test the images, and TestNG, which is used to generate the test results/reports in a detailed form.

Components of Selenium WebDriver Architecture 

The Selenium WebDriver architecture consists of the following components: 

1. Language-specific bindings: These are the libraries that allow you to use Selenium WebDriver in a specific programming language, such as Java or Python. The bindings provide a set of methods and classes that you can use to interact with the browser and execute test scripts. 

2. Browser drivers: These are the executables that allow Selenium WebDriver to communicate with the browser. Each browser has its own driver, and you will need to install the appropriate driver for the browser you want to use. 

3. JSON wire protocol: This is the communication protocol that is used to send commands from the bindings to the browser drivers and receive responses back. The protocol consists of a set of RESTful API endpoints that allow the bindings to send commands and receive responses. 

4. Browser: This is the web browser in which the tests are executed in. Selenium WebDriver supports a wide range of browsers, including Chrome, Firefox, Safari, and Edge. 

The Selenium WebDriver architecture allows you to use a variety of programming languages to write scripts that automate interactions with a web browser, enabling you to test the functionality and performance of your web application.

A Comparison between Selenium and QTP (now UFT) 

Selenium and QTP (now called UFT, or Unified Functional Testing) are both tools for automated testing of web applications. Here are some differences between the two:

1. Language support: Selenium supports a variety of programming languages, including Java, Python, C#, Ruby, and JavaScript, while QTP/UFT supports only VBScript. 

2. Browser support: Selenium supports a wide range of browsers, including Chrome, Firefox, Safari, and Edge, while QTP/UFT primarily supports Internet Explorer. 

3. Test design: Selenium is primarily a functional testing tool, and tests are typically designed as a series of steps that a user might take while interacting with the application. QTP/UFT is more geared towards regression testing, and tests are typically designed as a series of checkpoints that validate the application’s behavior. 

4. Object identification: Selenium uses a variety of techniques to identify elements on a web page, including element ID, class name, and CSS selector. QTP/UFT uses an object repository to store information about the objects in the application, and test scripts reference these objects using logical names. 

5. Integration with other tools: Selenium can be easily integrated with a variety of tools, such as build automation tools like Jenkins, while QTP/UFT has built-in integration with HP’s ALM (Application Lifecycle Management) tool. 

Overall, Selenium is a popular choice for functional testing of web applications due to its support for a wide range of languages and browsers, while QTP/UFT is more geared towards regression testing and has a more limited set of supported languages and browsers.

How to Choose the Right Selenium Tool for Your Needs 

Selenium is a suite of tools for automated testing of web applications. It includes several different tools, each of which has its own specific use cases and capabilities. Here are some things to consider when choosing the right Selenium tool for your needs: 

1. Language support: If you are using a specific programming language, you will want to choose a Selenium tool that supports that language. Selenium supports a variety of languages, including Java, Python, C#, Ruby, and JavaScript. 

2. Type of testing: Selenium includes tools for both functional testing and performance testing. Functional testing is used to verify that the application is working as expected, while performance testing is used to measure the performance of the application. Choose the tool that best fits your testing needs. 

3. Browser support: Selenium supports a wide range of browsers, including Chrome, Firefox, Safari, and Edge. Choose the tool that supports the browsers you need to test. 

4. Integration with other tools: If you are using other tools as part of your testing process, such as build automation tools or test management tools, you will want to choose a Selenium tool that integrates easily with these tools. 

5. Cost: Selenium is open-source and free to use. However, some of the tools in the Selenium suite may have associated costs, such as hosting fees or licensing fees. Consider these costs when choosing a Selenium tool. 

It is important to carefully evaluate your testing needs and choose the Selenium tool that best fits those needs. You may find that you need to use multiple Selenium tools in combination to achieve your testing goals. 

Conclusion 

Selenium is a suite of tools for automated testing of web applications. It allows you to write scripts in a variety of programming languages to automate interactions with a web browser and test the functionality and performance of your web application. Selenium includes several different tools, each of which has its own specific use cases and capabilities. 

To get started with Selenium, you will need to install a browser driver and a Selenium library in the programming language of your choice, and then you can begin writing and executing test scripts. Selenium is a powerful tool that can help you ensure the quality and reliability of your web application, and it is widely used in the software testing industry.

Frequently Asked Questions:

What is Selenium? 

Selenium is a suite of tools for automated testing of web applications. It allows you to write scripts in a variety of programming languages to automate interactions with a web browser and test the functionality and performance of your web application. 

What languages does Selenium support? 

Selenium supports a variety of programming languages, including Java, Python, C#, Ruby, and JavaScript. 

What browsers does Selenium support? 

Selenium supports a wide range of browsers, including Chrome, Firefox, Safari, and Edge. 

Is Selenium free to use? 

Yes, Selenium is open-source and free to use. 

What is Selenium WebDriver? 

Selenium WebDriver is a tool for automating web browser interactions. It is one of the tools in the Selenium suite of tools for automated testing of web applications. 

Can I use Selenium for performance testing? 

Yes, Selenium includes tools for performance testing, such as Selenium WebDriver and Selenium Grid, which allow you to measure the performance of your web application. 

How do I get started with Selenium? 

To get started with Selenium, you will need to install a browser driver and a Selenium library in the programming language of your choice. You can then begin writing and executing test scripts. You can find more information on how to install and use Selenium on the Selenium documentation website.