Types of Software Testing


Software testing is the process of testing a software product to verify its correspondence between the actual and expected behavior of the program. In this article, we will explore the various types of testing.

Main functional types of testing 

Functional testing

Functional testing is essentially the process of verifying that the software can perform the tasks required by users. Functional tests can be conducted at all levels of testing (component, integration, system, acceptance). The tasks performed by the software are determined by functional requirements. 

Functional requirements include: 

  • Functional suitability; 

  • Accuracy; 

  • Ability to interact; 

  • Compliance with standards and rules; 

  • Security. 

The advantage of this type of testing is that it simulates actual use of the system. However, one should not forget about the risk of missing logical errors in the software, as well as the probability of excessive testing. 

Security and Access Control Testing

This is also a functional type of testing aimed at verifying the security of the system, as well as analyzing risks associated with various types of attacks. The overall security strategy is based on three principles — Confidentiality, Integrity, and Availability.  

Confidentiality refers to restricting access to a resource to a specific group of people. For example, the appearance and functionality of many websites will differ for authorized and unauthorized users.  

Integrity means that a resource can only be changed in a certain way and by a certain group of users. In case of data damage, there is an assessment of how important the data recovery procedure is.  

Availability represents the requirements for how accessible resources should be to authorized users, objects, or devices. The more critical the resource, the higher the level of availability.

Interoperability Testing

Compatibility Testing and Integration Testing are included in it. Interaction testing checks the application's ability to work with one or more components or systems. Software with good interaction capabilities will easily integrate with other systems without requiring significant modifications. 

Main types of non-functional testing 

Non-functional testing is aimed at verifying the feasibility of non-functional requirements, which include: 

  • Performance; 

  •  Usability; 

  • Portability (installation); 

  • Reliability (failure/recovery). 

Non-functional testing does not test the system for performing functions that the customer wants. Instead, it allows controlling global properties: 

  • system performance under various loads; 

  • application scalability requirements;  

  • adaptation of the application to different platforms; 

  • guarantee of continued application operation even in unforeseen situations. 

Performance and Load Testing

This is automated testing that simulates the work of a certain number of users on a resource. It also has its types:  

  • Load testing. Determining the scalability of the application under load. In this case, the time of operation execution, the intensity of execution, the number of simultaneously working users, the boundaries of acceptable performance, and performance under different types of loads (high, maximum, and stress) are measured;.

  • Stress Testing. A test to determine how well the application and the s…

  • Volume Testing. A test to assess performance when data volume in the database is increased. 

  • Stability/Reliability Testing. A test to check application performance during prolonged (hours-long) testing with moderate load. The most important aspect of this testing is checking for memory leaks, server restarts under load, and other factors that directly affect stable software operation. 

Installation testing

This type of testing is aimed at ensuring successful installation and configuration, as well as updating or uninstalling software.  

It is important to note that full testing in this case will not only involve checking the successful operation of the installer, which we have become accustomed to. Installation Testing in this case involves writing an installation plan that includes steps for installing the application and steps for rolling back to the previous version. It is also important to remember that the installation plan itself must undergo testing.  

Usability Testing

Testing aimed at evaluating the ease of use, ease of learning, and attractiveness for potential users of the developed product. 

Failover and Recovery Testing

This is a test of the product's ability to resist and successfully recover from possible failures caused by software errors, hardware failures, or communication interruptions. 

Configuration Testing

This is a test of software performance on different systems. For example, on declared platforms, with supported drivers on different computer configurations.  

The goals of such testing depend entirely on the project being tested. In the case of profiling system performance, we will need to determine the optimal hardware configuration, while for a system migration project, we will need to focus on compatibility.  

Depending on the testing goals, all types of testing can be divided into three types: functional, non-functional, and change-related.

Change-Related Testing

After fixing a defect, it is necessary to perform retesting to ensure that the changes made have indeed solved the problem. Additionally, any project requires confirmation of the application's functionality.

Smoke Testing

A short cycle of checks performed to confirm that the installed application starts and performs basic functions after assembly. It is carried out based on the results of superficial testing of only important modules of the application, to check for the ability to perform required tasks and the presence of quickly identifiable critical and blocking defects.  

This testing is performed before Regression Testing and therefore covers less functionality during testing. 

Regression Testing

This is a check of changes to confirm that the existing functionality in the application works the same as before intervention.  Regression testing records the correction of found defects and the absence of new bugs in the system.

Regression testing can be both functional and non-functional.  


In this article, we have looked at the main types of testing. For convenience and memorization, keep this table:






Functional testing 

Ability to simulate actual system operation.


High probability of redundant tests.

Chance of missing logical errors in software.  


 Security testing 

Confidence that the chances of external damage to the system are minimal. 

Regardless of the number of tests, it is impossible to be sure that the system is fully protected against any attacks.  

Interaction testing

Includes compatibility and integration, facilitating software implementation. 


High chances of not covering all types of integration and compatibility.

The need for constant consideration of device updates/obsolescence.  



Performance testing 


Automated testing, which facilitates manual testing and saves time.

Software protection due to readiness for situations leading to system overload. 



Automated testing requires serious programming skills, as well as knowledge of network protocols, various application servers, and databases.

Considered one of the most difficult tests, it requires a lot of time for training. 


Installation testing 

Helps avoid problems with installing software in an industrial environment (inability to install software, data loss after installing a new version, inability to roll back a version). 

Additional time for development or the need to attract additional resources to perform these tasks.

Usability testing

Usability of internal objects, classes, methods, and variables is tested, as well as the ease of changing, expanding the system, and integrating it with other modules or systems.

It is not always possible to conduct testing with a "gray/black box" approach.

There is a high chance of losing scenarios. 

Failure and recovery testing 

Situations are provided for maintaining the integrity of user data in the software.

It is impossible to anticipate all situations. 

Configuration testing  

The use of a coverage matrix.

Determining the optimal hardware configuration, testing the test object for compatibility.

Low costs with automation. 

The more requirements for the application's operation under different workstation configurations, the more tests we will need to conduct.

The need for automated tests.  

Change-Related Testing

Smoke testing 

Relatively low time spent on testing.

Priority on guaranteeing the operation of the main functionality.

Superficial testing.

Intentional skipping of some functionality in coverage.  

Regression testing 

Ensuring that changes in the new version of the application do not damage existing functionality.

Acceleration of re-tests.

Guarantee of detecting defects at early stages of development.  


Increased amount of time and activity on the project.

Loss of concentration during constant re-testing.