What is Compatibility Testing? Forward & Backward Testing (Example)

Software TestingAutomation TestingTesting Tools

This part will teach us what compatibility testing is, why we use it when we should conduct it, the many types of compatibility testing, the compatibility testing method, and compatibility bugs and tools.

What exactly is compatibility?

Compatibility is simply the capacity to coexist or live together. Oil is not often compatible with water; however, milk may be easily mixed with water.

Compatibility Testing

Compatibility testing is a form of software testing that determines if your program can operate on various hardware, operating systems, applications, network settings, or mobile devices.

Non-functional testing includes compatibility testing.

Compatibility Tests and Their Types

  • Hardware − It validates software to ensure that it is compatible with various hardware configurations.

  • Operating Systems − It verifies that your program is compatible with various operating systems such as Windows, Unix, and Mac OS.

  • Software − It validates your produced software to ensure that it is compatible with other software. For instance, the MS Word program should be compatible with other applications such as MS Outlook, MS Excel, VBA, and so on.

  • Network − The evaluation of a system's performance in a network with various characteristics such as bandwidth, operating speed, and capacity. It also tests the program on various networks using all of the previously specified criteria.

  • Browser − It tests your website's compatibility with several browsers such as Firefox, Google Chrome, Internet Explorer, and others.

  • Devices − It tests your software's compatibility with various devices such as USB port devices, printers and scanners, other media devices, and Bluetooth.

  • Mobile − Verify that your program is compatible with mobile platforms such as Android and iOS.

  • Versions of software − It validates your software application's compatibility with various software versions. For example, ensure that your Microsoft Word is compatible with Windows 7, Windows 7 SP1, Windows 7 SP2, and Windows 7 SP3.

In Compatibility Testing, there are two forms of version checking −

Compatibility Testing − Forward and Backward Testing

Testing for Backward Compatibility

Backward compatibility testing is a technique used to validate the behavior and compatibility of newly produced hardware or software with previous versions of the hardware or software. Because all of the changes from prior versions are known, backward compatibility testing is considerably more predictable.

Testing for Forward Compatibility

Forward compatibility testing is a procedure that verifies the behavior and compatibility of produced hardware and software with later versions of the hardware and software .Forward compatibility testing is difficult to forecast since the modifications that will be made in subsequent versions are unknown.

Why do we perform compatibility testing?

We pushed the program to production once it was stable. It may be used or accessed by numerous people on different platforms, and they may encounter certain compatibility difficulties; to avoid these issues, we perform one round of compatibility testing.

The procedure for assessing compatibility

We're running an O.S (Operating system) compatibility test right now. The customer will first provide a functional demand as well as a nonfunctional requirement.

Following receipt of the non-functional need, the one base platform will make a decision based on the most widely used platform.

Following that, the test engineer will begin functional testing on the basic platform until the application has achieved functional stability. We need to test the program on a separate platform, thus we have VMware software for that.

Note1 − VMware software − Using VMware, we may partition a real system into many virtual machines that can be accessed at the same time.

For compatibility testing, we will install all essential operating systems and browsers on a VM Server and access that server via a Remote Desktop connection.

We connect to the VMware setup remotely, and then the test engineer does one cycle of compatibility testing on the platform and checks the end-to-end flow.

The end-to-end flow will continue until the application is stable, apps function well on all required platforms, and the customer is handed off.

Note2 − For browser compatibility testing, we don't need to use VMware because several browsers may be installed on a single computer and used concurrently.

In the event of several versions of the same browser, we must use a VMware setup since multiple versions of the browser cannot be accessed concurrently from a single machine.

We can do software compatibility testing on a variety of systems.

Bug/issue with compatibility testing

These are bugs that exist on one platform but do not occur on another.

In general, compatibility flaws are user interface difficulties; some examples of U.I issues are as follows −

  • Alignment issue

  • Overlap issue

  • Scattered issue

  • Look and feel issue

Alignment issue

The alignment problem occurs when a page element is not properly aligned, as seen in the figure below −

Overlap issue

When one property overlaps another, it may occur when we try to open the program on multiple systems or browsers, as seen in the figure below −

Scattered issue

When the test engineer does compatibility testing on the program, and that application is not compatible with all browsers and platforms, as seen in the figure below, various difficulties may occur −

In compatibility testing, we examine the functionality, integration, and end-to-end flow on many platforms.

Compatibility issue − When an application feature does not operate in one operating system but works well in another. It occurs because software developed by the developer does not operate on only one platform but works perfectly on all others.

Functionality issue − When a feature does not operate across all operating systems/platforms, this is referred to as a functional problem. It is sometimes referred to as a functionality fault problem.

The test execution report for compatibility testing looks like this −

Test execution report for Compatibility Testing

Windows VistaWindows XPWindows 7
Step 1Test Case NameStatusCommentsStatusCommentsStatusComments

Various Browsers

Windows XP
Mozilla FirefoxOperaInternet Explorer

Tools for checking compatibility

The following are some of the most widely used compatibility testing tools −

  • LambdaTest It is a cloud-based open-source browser compatibility testing tool. We may use this tool to test our web application on nearly all mobile and desktop browsers. LambdaTest has a snapshot functionality that enables us to capture full-page screenshots of our web pages. In this tool, we can test our application on actual browsers, and the user may choose from a huge variety of mobile and desktop browsers to evaluate the program's compatibility.

  • BrowserStack This tool allows us to evaluate the interoperability of websites and mobile applications across many browsers and platforms. This allows us to test a web application in multiple browsers as well as mobile applications such as Android and iOS on all mobile devices. BrowserStack tools' major products are Live, Automate, App Live, and App Automate; with the assistance of these tools, we can keep costs down. These tools assist us in lowering the time, cost, and maintenance overhead involved with testing.

  • BrowseEMAll This program is a cross-browser testing tool that can execute the application on several operating systems such as Linux, Windows, and macOS. It is used to test the program on all mobile and desktop browsers, and we may use it directly on our local system and on our local network. We can also do regression and visual testing without any network delays, as well as record and play automated tests across a large number of desktop and mobile browsers.

  • TestingBot This program is used to run tests on a variety of browsers, including Firefox, Chrome, Edge, Internet Explorer, and Safari. This allows us to compare screenshots from different browsers and systems and evaluate the application's responsive layout. It will give a wide number of browser versions for usage in automation testing right away.


The most essential use of compatibility testing is to guarantee that produced software works in a variety of setups (as stated in requirements documentation). This testing is required to check whether or not the application is compatible with the client's environment.

Updated on 24-Sep-2021 14:52:06