A Guide to Software Compatibility Testing: What & Why?

Testing across multiple OS versions, device types, and browser configurations can be complex and time-consuming, but with Testsigma you can run tests in parallel on real devices, integrate them into your CI/CD pipeline, and achieve broader coverage with faster feedback.

What is Software Testing Compatibility?

Software compatibility testing is a non-functional testing. To simply put, it verifies whether or not an application works across various hardware, operating systems (OS and network configurations). 

At the heart of it, software compatibility testing answers questions on how well software performs on different devices for example, how a Samsung Galaxy S23 compares to an iPhone 4 and that it will meet user requirements in diverse environments.

With a lot of devices, browsers, and OS versions, this testing is crucial. It addresses the challenges of device and browser fragmentation and ensures the software delivers a consistent user experience. No matter the device or platform, this makes it prerequisite in today’s diverse digital landscape.

Importance of Software Compatibility Testing

Today, users interact with software across a wide range of devices, operating systems, and browsers. This makes software compatibility testing a necessary part of the development and QA process. It helps teams ensure that the software works as expected in different environments, without unexpected issues. Here’s why compatibility testing matters more than ever today:

1. Works Across Devices and Platforms

Apps are used on various screen sizes and operating systems. System compatibility testing helps identify issues that may appear when software is run on different hardware or configurations.

2. Keeps the User Experience Consistent

A user opening the same app in Chrome, Safari, or Edge shouldn’t face layout or performance differences. Browser compatibility testing helps ensure consistent functionality across browsers.

3. Supports Older Versions

Not all users are on the latest OS or browser version. Backward compatibility testing helps check how the application performs on older systems that are still in use.

4. Reduces Risks During Updates

With regular updates and releases, new changes can unintentionally break things in specific environments. Compatibility tests help teams catch these issues before deployment.

5. Helps Reach More Users

Running mobile compatibility tests ensures that apps work across different phones and tablets, helping teams avoid losing users due to compatibility issues.

6. Lowers Maintenance and Debugging Effort

Catching compatibility issues early through testing saves time later during debugging and support. It also reduces the risk of production incidents caused by environment-specific bugs.

Best Tools for Software Compatibility Testing in 2025

How to Perform Compatibility Testing – Manual and Automated?

Compatibility testing can be performed using both manual and automated approaches. The steps differ depending on the approach. Automation is the best approach if you’re looking for comprehensive test coverage and faster testing. With Testsigma, you can achieve up to 90% test coverage by running tests across 3000+ real devices, platforms, and browsers on the cloud.

Steps to Execute Manually:

1. Have the list of target devices/operating systems/databases/browsers that need to be supported. Ensure that all selected combinations are available.
2. Select the test cases that need to be executed on all the selected combinations in step 1.
3. Execute the selected test cases on the selected combinations.

Steps to Execute Via an Automated Tool:

1. Have the list of target devices/operating systems/databases/browsers that need to be supported. Ensure that all selected combinations are available.
2. Ensure that you can automate the tests to be executed on the devices available in step 1.
3. The test cases that need to be executed for this testing should be automated in the test automation tool of your choice.

Schedule the execution of test cases created in step 3, as and when needed.

When to Automate?

Automation of compatibility testing is key to the achievement of a complete and effective assessment of software in a wide range of environments. 

So what a good test suite for compatibility should include? Here it is:

Browser Compatibility: Makes sure the application works well with different browsers and their versions.

Device Compatibility: It tests performance on various devices such as smartphones, tablets, and desktops with different resolutions and screen sizes.

Hardware Compatibility: It evaluates the compatibility of the app with various hardware configurations such as processors and memory.

OS Compatibility: It checks operations on different operating systems and their versions— Windows, Linux, Android, and iOS.

Network Connectivity: It should be tested under different network conditions from 5G to no network at all.

Geolocation/Localization: It should also be tested from different geographical locations and regions.

Considering how intricate tests can be across these variables, manual testing across them is often impractical because of time and resource constraints, as well as issues of scalability. 

Automation simplifies the process by making it possible to carry out simultaneous tests in multiple environments. Automating compatibility testing not only quickens the process but also improves its accuracy. 

Checklist for Compatibility Testing

• Validate your HTML, XHTML, and CSS. No open tags. 
• Validate the SSL certificate and ensure it is compatible with most browser versions
• Validate the site or app’s responsive design, 
• Validate all site/app fonts, design elements, and fields. 
• Verify that all layouts, styles, and design are consistent across user environments.
• Validate that images load and render accurately. 
• Check that all fonts, colors, headers and footers are consistent. 
• Ensure that spacing between text and images appears as expected across versions. 
• Check that that scroll, zoom in/zoom out, mouse hover functions as well as the drop down menus are working properly. 
• Ensure that tables and grids are well-aligned, and that pop-ups (if any) appear as expected.

Types of Software Compatibility Testing

1.Backward Compatibility Testing:

Ensures the current software version is compatible with earlier ones. It involves scenario testing, data migration checks, and ensuring a smooth user experience during upgrades.

Backward compatibility testing is a practice that verifies whether new changes or updates to a software product remain compatible with its previous versions. It ensures that users can seamlessly transition to the latest release without encountering unexpected issues or disruptions.

During backward compatibility testing, testers assess various aspects of the software, such as data migration, system configurations, functional behavior, user interfaces, performance, security measures, and API integrations. This comprehensive testing process helps guarantee that users can transition seamlessly from older versions to the new one, without sacrificing user satisfaction or encountering data loss.

2.Forward Compatibility Testing:

Verifies the software’s compatibility with future versions, covering aspects like API compatibility, feature alignment, and performance on upcoming platforms. Both types are crucial for a comprehensive compatibility testing strategy.

Software must be tested for compatibility on various functional and non-functional levels, as explained above. A few compatibility testing types, based on these variant levels, are listed below:

What is Hardware Testing?

In simplest terms, these tests check how the software responds to and works with various hardware configuration commonly used by it’s target user base. The aim is for the site/app to be compatible with as many hardware configurations as possible and realistically required.

What is Network Testing?

How is your app going to work when using 2G internet, as opposed to 5G? Perhaps it needs to suspend certain features/design elements from loading so as to continue functioning. This form of compatibility testing checks that these optimizations work exactly as expected in real-world usage. Its aim is to ensure that the software works with different connectivity conditions without compromising user experience too drastically. 

What is Operating System Testing?

This sub-category of compatibility testing verifies if software functions and appears as it is expected to, when running on different operating systems and their versions. This includes desktop and OS-specific OSes, and different versions of each OS. 

What is Device Testing?

This form of testing verifies if the software works optimally on different devices with their variant manufacturing models, screen sizes, and resolutions. Responsive testing is an important part of device testing.

What is Mobile Compatibility Testing?

In this case, you’re testing if your software is aligned and fully functioning on different mobile devices, browsers, and OSes. Needless to say, there is quite a bit of overlap with browser, device, hardware, and OS compatibility testing. 

What is Browser Testing?

There are many popular browsers (other than Chrome) that you use base will leverage to access whichever website you are developing. This form of testing ensures that said site works without hassle on all/most of these browsers, as well as the different versions of each of those browsers. 

What is Version Testing?

All software in which YOUR software is expected to work will be updated regularly. For example, Chrome will launch updated versions consecutively (and quite frequently these days) for better usability and security, as will every other browser. The same goes for OSes. Your site or app must continue working well with every single version, updated or older. To ensure that it does so, you have to undertake version compatibility testing. 

Advantages of Compatibility Testing

• Verifies that an app or site is ready for usage across your entire target user base. 
• Ensures that the app or site works in different user conditions – low network connectivity, different browser-device-OS combinations, etc. 
• Ensure that users can access and utilize the app or site from all authorized/approved locations, be it from different countries, states,, or local areas. 
• Ensures that the app complies with and meets regulatory standards for different areas and cultures. 
• Ensures that the app or site is aligned with different cultural sensitives, customs, and preferences.

Test Cases for Compatibility Testing

Before we write compatibility test cases, let’s understand the categories. Each category focuses on different aspects, such as,

OS testing – checks how the application works on different operating systems. It has two sub-categories,

Forward compatibility testing – tests the application’s behavior on the latest OS versions

Backward compatibility testing – tests the application’s behavior on older OS versions

Cross-browser testing – checks how the applications work on different browsers and versions.

Network testing – evaluates how the application works on various network conditions

Device testing – shows how the application functions on different device specifications.

Below is a document showing how to perform compatibility testing with Testsigma: Test Plan for Cross Browser Testing

Let’s create compatibility test cases for the below web page. 

Below are some of the cross-browser test cases that check the cross-browser compatibility of the application on different browsers,

• Verify that the web pages render correctly on different browsers.
• Check for differences in font rendering, spacing, and layout.
• Test the application at different zoom levels to ensure content remains readable and accessible.
• Test form submissions and validation on different browsers.
• Ensure that form elements, such as text fields, checkboxes, and radio buttons, work properly.
• Test on older browser versions to ensure backward compatibility.
• Verify that scrollbars appear and function correctly.

Common Compatibility Testing Defects

Compatibility bugs refer to the issues that occur on one platform but not on another. For example, a bug that surfaces on Windows but not on Mac or other platforms. Some of the common types of bugs in software compatibility testing include,

• Changes in UI appearance (look and feel)
• Modifications in font size
• Change in color and CSS style 
• Alignment-related issues
• Broken frames or tables
• Changes in button size or other design elements
• Anomalies with scrolling and content placement
• Overlapping content/design elements

What is the Most Challenging Part of Compatibility Testing?

Undoubtedly, the most challenging part of this testing is actually accessing all the browsers, devices, OSes, network conditions, and other elements required to replicate actual specifics of the production environments within your testing ecosystem. 

Unless you have a massive budget at hand, you cannot buy/maintain/update the thousands of devices you need to run a comprehensive compatibility test suite. Thankfully, with tools like Testsigma at hand, you don’t have to. 

Testsigma for Automated Compatibility Testing

Testsigma is a codeless, AI-driven test automation platform that enables teams to test web, mobile, desktop, APIs, Salesforce, and ERP software like SAP in one place. One of the biggest challenges in software compatibility testing is the sheer number of environments teams need to test for, especially when dealing with multiple OS versions, device types, and browser configurations. This often leads to bottlenecks, missed coverage, or slow test cycles. 

Testsigma reduces that complexity by providing access to 3000+ real devices and letting teams run tests simultaneously across them, all while fitting into the CI/CD pipeline. This, in turn, offers broader test coverage with less effort and faster feedback.

Why Testsigma is the Best Choice?

1. Real Devices, Browsers, and OSs

Testsigma provides access to over 3000+ real combinations of devices, browsers, and operating systems. This helps ensure thorough system compatibility checks across environments your users actually use.

2. Test Cases in Plain English

Testers can write and maintain test cases in simple English. This makes compatibility testing more accessible for QA teams, business analysts, and others without programming skills.

3. Parallel Execution

Tests can run simultaneously across multiple environments. This saves time during large-scale compatibility test cycles and speeds up feedback without reducing coverage.

4. Built-in CI/CD Integration

Testsigma integrates with tools like Jenkins, GitLab, and GitHub Actions. Compatibility tests can run automatically during every build, supporting early detection of environment-specific issues.

5. Environment-Specific Debugging

Each test run includes logs, screenshots, and video recordings for the exact device and browser used. This helps teams check compatibility errors faster and debug with context.

6. Unified Platform for All Testing Needs

Web, mobile, API, desktop, and Salesforce tests can be created and managed in one place. This simplifies test management for teams performing multiple types of software compatibility testing.

7. Detailed Reporting and Insights

Testsigma offers test reports with filtering and trend analysis. Teams can quickly identify patterns in compatibility test failures and track stability across releases.

Wrap-Up Time!

Here you go with a summarization.

Software compatibility testing when done properly, helps to prevent costly issues. Not only does this improve user satisfaction through efficient automation, but a great deal of time can be saved (and esp with compatibility testing tools like Testsigma, it’s often easier).