19 Types of Software Testing in Software Engineering-1

19 Types of Software Testing in Software Engineering

Software testing is like a skilled craft. Just as a craftsman must understand their tools, a software tester needs to know the testing tools available. We’ve made a list of 9 types of software testing and the tools they use. This helps QA analysts and others in software testing understand their work better.

Table of contents

What is Software Testing?

Software testing is simply the process of uncovering mistakes or issues in a product, whether it’s a mobile app or a website. These problems could be bugs in the code, things missing from the requirements, or unexpected behaviour. Testing also checks if the product does what it’s supposed to do as expected.

Ideally, testing happens at every stage of building the product. But usually, it’s the last step before releasing the product to the public. Testers use both manual methods (where they check things themselves) and automated tools (where software does the checking) to make sure the final product works well.

In organizations, there are three main types of people who do testing:

  • Business Testers: These folks are part of the business team and might not have deep technical skills. They often do manual testing or exploratory testing, where they explore the product to find issues. As they learn more, they might start using automated tools too.
  • SDET (Software Developer in Testing): These testers are experienced in testing and coding. They’re responsible for testing the product’s code, so they use tools and write code themselves to test the software thoroughly.
  • Software Developers: Developers also do testing, but their focus is more on creating tests at an earlier stage, like unit tests (testing individual parts of the code) and acceptance tests (checking if the software meets the requirements).

Why is Software Testing Important?

Let’s remember why software testing matters. Every successful software owes its success partly to the hard work of software testers. Here are three reasons why software testing is crucial:

  • Customer Satisfaction: Amidst all the coding, it’s easy to forget that users need to be happy with how the software functions. QA analysts and others in QA ensure this satisfaction.
  • Product Quality: Every creative process needs someone to spot mistakes. Writers have editors, filmmakers have editors, and software developers have QA teams to provide a fresh perspective and catch errors.
  • Security: This is increasingly important as time goes on. Users want assurance that their data is safe within the software. Part of QA is ensuring that users can trust the software with their information.

Software Testing Methodologies

Software testing methodologies can be broadly categorized into two main types: static testing and dynamic testing. Let’s understand the difference between these two approaches and where they fit into the software development cycle.

Static Testing

Static testing is conducted early in the development cycle to find bugs before they become significant issues. It’s a cost-effective way to identify and address problems in the software. Static tests can be performed without the need for fully functional software, which makes them particularly useful in the initial stages of development.


Static tests can be carried out in two ways:


  • Manual Examinations: A QA analyst or tester analyzes the code or documents manually to identify potential issues.
  • Automatic Analysis: Testing tools are used to automatically check the program documents and flag any errors.


Key points about static testing:

  • It is performed without executing the code.
  • It is cost-effective.
  • It ensures that the software meets verification specifications.
  • It helps in identifying the root cause of bugs.


Static testing primarily involves document reviews, where either written descriptions of the product (such as software design documents) or the program source code are examined. 


Here are some common techniques used in static testing:


  • Informal Review: A casual review where the team looks over the documents and provides comments without strict guidelines or documentation.
  • Walkthrough: The author of the code guides the QA team through the document, allowing for informal discussions and addressing any questions or concerns.
  • Technical Review: Technical experts come together to review the technical specifications of the code, ensuring that the final product meets the required specifications.
  • Inspections: The most formal type of review where a team of trained moderators thoroughly inspects the documents during a meeting. Any identified bugs are formally documented and logged for review, with follow-up checks to ensure they are addressed.


Static testing reviews involve the entire QA team, allowing for a wide range of perspectives and suggestions for improvements. This approach ensures that all team members are updated on the project’s progress and design, while also facilitating early bug detection and resolution.


Teams typically opt for static testing when they are:

  • In the early stages of development.
  • Looking for a cost-effective bug-finding method.
  • Working with software that is not ready for execution.
  • Wanting to catch errors early in the development process.

Dynamic Testing

Dynamic Testing

Dynamic testing is a type of software testing that involves running the code. Unlike static testing, which can be done without executing the code, dynamic testing requires the software development to be further along in the production cycle.


The benefit of dynamic testing is that it allows QA analysts to observe how the software behaves in a real-world scenario. It checks things like functional behavior and CPU usage to ensure that the expected outcome matches what actually happens when the software is running.


Here are the four main steps involved in dynamic testing:


  • Unit Testing: In unit testing, the software is divided into its smallest components and tested individually. This ensures that each part is working correctly, making it easier to isolate and fix any bugs found.


  • Integration Testing: After unit testing, the components are assembled into groups and tested again. Integration testing ensures that these components work together properly, similar to assembling the parts of a car and testing how they interact.


  • System Testing: This stage involves testing the complete and fully integrated software to ensure it meets the specified requirements and functions as intended.


  • Acceptance Testing: The final stage of dynamic testing is acceptance testing, which verifies that the software meets the requirements and is ready for release. It serves as a final check to ensure no errors have slipped through the previous testing stages.


The stages of dynamic testing are:


  • Unit Testing
  • Integration Testing
  • System Testing
  • Acceptance Testing



Verification testing, which is similar to static testing, verifies documents and code without running them. Validation testing, similar to dynamic testing, confirms that the software meets quality standards by executing it.


Understanding these concepts is crucial for QA analysts as they delve into the various types of software testing.

19 Types of Software Testing IN Software Engineering

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Below are the 19 types of Software testing in software engineering that every QA analyst should know


  1. Black Box
  2. White Box
  3. Grey Box 
  4. Automated Testing
  5. Unit Testing
  6. Regression Testing
  7. Exploratory Testing
  8. Functional Testing
  9. Usability Testing
  10. End to End Testing
  11. Interactive Testing
  12. Integration Testing
  13. Load Testing
  14. Non-Functional Testing
  15. Sanity Testing
  16. Security Testing
  17. Single User Performance Testing
  18. Smoke Testing
  19. Stress Testing

Black Box

Black box testing is a method of software testing where the tester doesn’t know the internal workings or design of the software being tested. It’s like being an audience member in a movie, knowing what something is supposed to do without knowing its inner workings.


For example, imagine testing a time tracking software. A black box tester would use the software without knowing how it’s built, just like an ordinary user. They’d try out different features and menus to ensure everything works as expected.


Benefits of black box testing include:


  • No Programming Knowledge Required: Testers don’t need to be experts in programming languages because they’re testing from a user’s perspective.


  • Unbiased Review: Since the testing is done by the QA team, who are separate from the developers, it provides an impartial review of the software.


  • Quick Start: Testers can start testing without needing to understand the software’s development process, leading to faster testing turnaround.

White Box Testing

In white box testing, the QA member has a deep understanding of the internal structure and design of the software being tested. They act like an inspector, ensuring every part of the program functions correctly. White box testing is also known as clear box testing because the tester can see and understand the interactions between different parts of the software. Unlike black box testing, white box testers focus less on user experience.


Some benefits of white box testing include:

  • Tests can be conducted in the early stages of development, even if the graphic user interface (GUI) is not fully functional.
  • Tests are more thorough and intentional compared to black box tests.
  • In the Pulp Fiction example, the white box tester is like Tim Roth’s character, directly observing what’s inside the briefcase.

Grey box Testing

Grey box testing is a unique approach where the tester possesses some knowledge of the software’s internal structure and design (similar to white box testing), while still evaluating the software from an end user’s perspective (like black box testing).


In grey box testing, the testing strategy is developed by examining the software’s internal structure, but the actual testing is conducted using the software’s user interface.


If we draw a comparison to the famous Pulp Fiction scene, the grey box tester is neither the audience nor Tim Roth. Instead, they take on the role of Quentin Tarantino, having some insight into what’s inside the briefcase but still approaching it with an outsider’s perspective.

Automated Testing

Automated testing involves using software to carry out tasks without the need for manual intervention by a tester.


In manual testing, the tester typically writes the code they want to execute or plans the software path they need to check. Automated tests, however, handle these tasks on behalf of the tester. Here are a few automated software and QA tools that QA analysts should be familiar with:

  • Selenium
  • Cucumber
  • Katalon Studio


For a comprehensive review of automated testing tools, you can explore the list of Best Automated Testing Tools that you should consider using.

Unit Testing Tools

Unit testing tools are essential for verifying the functionality of each individual component of the software. Ensuring thorough unit testing is crucial because any flaws discovered later can cause significant setbacks for the development team.


In essence, unit testing focuses on testing small, isolated units of code to ensure they function correctly in isolation. By using unit testing tools, developers can identify and address issues early in the development process, reducing the risk of larger problems arising later on.

Regression Testing

Regression testing tools are used to execute previously conducted tests on new versions or builds of the software. The purpose is to ensure that the software still behaves as expected after changes have been made. By running regression tests, developers can detect any unintended side effects or issues caused by modifications made to the software.


This type of testing safeguards against unforeseen consequences by verifying that alterations made at one point in the software do not inadvertently impact other areas. In essence, regression testing helps maintain the stability and reliability of the software throughout its development lifecycle.


For QA analysts, embracing regression testing as a necessary step is akin to taking a step back to ensure long-term progress. It prevents potential setbacks and ensures that the software remains on track for success.

Exploratory Testing

Exploratory testing is a testing approach that doesn’t rely on extensive planning. Unlike traditional testing methods where test cases are meticulously planned before execution, exploratory testing involves testers exploring the software without a predefined plan.


The advantage of exploratory testing lies in its flexibility. Testers can adapt to their findings in real-time without the need to create new test cases. It encourages collaboration, brainstorming, and problem-solving on the fly.


As agile development practices have gained popularity, so has exploratory testing. By allowing QA testers to rely on their intuition, this approach often uncovers interesting bugs that may have been overlooked in traditional testing methods.

However, it’s important to note that exploratory testing demands a high level of creativity from testers. They must be able to think outside the box to effectively uncover potential issues within the software.

Functional Testing

Functional testing ensures that the system software aligns with the project’s initial requirements before development begins.


During functional testing, the software tester verifies that the inputs provided yield the expected outputs. Typically conducted during the final stages of testing, such as system or acceptance testing, functional testing focuses solely on ensuring that the software functions correctly without delving into its internal workings.


It’s worth noting that functional testing falls under the category of black box testing, as it primarily concerns itself with the software’s functionality rather than its underlying mechanisms.

Usability Testing

Usability testing ensures that the design choices of the software are both functional and intuitive for users.


For example, if you anticipate that many users will want to back up their documents every half hour, it’s important to place the backup function in an easily accessible location rather than burying it behind multiple sub-menus.


Often, software may function perfectly and fulfill a critical market need, but it becomes challenging for users to navigate due to poor usability. This highlights the importance of conducting usability testing during the software testing phase.


Ultimately, no matter how technically impressive a piece of software may be, its success in the market depends on whether users enjoy using it. Usability testing plays a crucial role in ensuring a positive user experience and, consequently, the software’s market acceptance.

End-to-End Testing

This technique assesses the entire workflow of an application from start to finish to ensure everything operates as intended.

Interactive Testing

Also known as manual testing, this method allows testers to create and conduct manual tests for scenarios not covered by automation, collecting results from external tests.

Integration Testing

Integration testing confirms that an entire integrated system meets specified requirements. It’s conducted in a combined hardware and software environment to verify the overall system functionality.

Load Testing

Load testing examines how a software application behaves under simultaneous access by multiple users, assessing its performance under such conditions.

Non-Functional Testing

Non-functional testing evaluates system readiness based on parameters like performance, accessibility, and user experience, which aren’t addressed by functional testing alone.

Sanity Testing

After bug fixes, sanity testing ensures that the identified issues are resolved and that no new problems arise due to the changes.

Security Testing

Security testing identifies vulnerabilities within the system to ensure that the software and application are free from potential threats or risks, safeguarding against data loss, revenue loss, or damage to reputation.

Single User Performance Testing

This testing verifies that the application performs adequately under specified thresholds without any system load. It establishes benchmarks for performance under load conditions.

Smoke Testing

Smoke testing validates the stability of a software application by checking critical functions in the initial build to ensure proper operation.

Stress Testing

Stress testing pushes the software beyond normal operational capacity to evaluate its behavior and performance under extreme conditions.

5 key software testing steps every engineer should perform

Shift-left testing” refers to the practice of conducting more software testing during the early stages of software development. This approach aims to identify and fix defects sooner, ultimately saving the business from costly bugs down the line.


Typically, shift-left testing involves increased involvement by quality assurance (QA) engineers during the development phase. This means detecting defects early, before software engineers hand over the program for extensive testing by QA.


One common aspect of shift-left testing is the emphasis on developing and executing more automated testing of the user interface (UI) and application programming interfaces (APIs). This helps catch issues earlier in the development process.


However, regardless of the testing approach, there are fundamental software testing steps every developer should perform before presenting their work to others. These steps include:

Basic Functionality Testing

Ensure that every button and feature works as expected, and that basic inputs do not cause the software to crash. This is typically done using both manual and automated testing methods.

Code Review

Have another developer review your code to uncover any potential issues or bugs. This step helps ensure code quality and consistency.

Static Code Analysis

Use tools that analyze source code without executing it to identify weaknesses such as security vulnerabilities or concurrency issues. This should be integrated into the development process.

Unit Testing

Write and run tests to verify that individual units of code (methods, classes, components) work as expected, using valid and invalid inputs. Unit tests should be run automatically as part of the development process

Single-User Performance Testing

Test the performance of the software under typical usage scenarios to ensure responsiveness. This can involve checking page load times and identifying any performance bottlenecks.


Finding the right balance between writing code and testing is crucial. Developers should allocate time for testing to prevent obvious bugs and maintain their reputation for delivering working software. This balance may vary for each developer, but investing time in designing, reviewing, and testing code is essential for producing high-quality, easy-to-use software.


In conclusion, the spectrum of software testing methodologies, ranging from unit and integration testing to security and performance testing, is essential for ensuring the quality and reliability of software products. By strategically combining these approaches, developers can enhance user satisfaction, minimize risks, and deliver robust solutions in today’s dynamic digital landscape, encouraging continuous improvement and innovation in software engineering practices.

Frequently Asked Questions

Software testing in software engineering refers to the process of evaluating a software application or system to ensure that it meets specified requirements, functions correctly, and is free from defects or errors.

Software testing is crucial in software engineering as it helps identify and rectify defects early in the development process, ensures the reliability and quality of the software, enhances user satisfaction, and minimizes the risk of software failures or malfunctions.

There are various types of software testing, including unit testing, integration testing, system testing, acceptance testing, regression testing, performance testing, usability testing, security testing, and compatibility testing.

Unit testing involves testing individual components or units of code to ensure they function correctly in isolation. It helps detect and fix bugs at an early stage, promotes code quality, and facilitates code refactoring and maintenance.

Integration testing verifies the interaction between different modules or components of a software system to ensure they work together as intended. It helps uncover integration issues, dependencies, and communication errors, ensuring the overall system functions smoothly.

Regression testing involves retesting the modified or updated parts of a software application to ensure that existing functionalities remain unaffected. It helps prevent the reintroduction of defects and maintains software stability across successive iterations or releases.

Performance testing evaluates the responsiveness, scalability, and reliability of a software application under various workload conditions. It helps identify performance bottlenecks, optimize system resources, and ensure that the software meets performance requirements and user expectations.

Security testing assesses the resilience of a software system against potential security threats, vulnerabilities, and attacks. It helps protect sensitive data, ensure compliance with security standards, and build trust among users, mitigating the risk of security breaches or data breaches.

Best practices for software testing include establishing clear testing objectives, designing comprehensive test cases, automating repetitive tests, conducting thorough documentation, collaborating effectively with stakeholders, and embracing continuous integration and continuous testing methodologies.