15 Different Types Of QA Testing You Should Know

Software testing consists of a very wide variety of testing techniques which are employed to serve a diverse purpose based on the Application Under Test (AUT), type of testing, or software characteristics. It aids teams in coming up with appropriate test plans and makes software dependable.

In this article, we will group various testing types, discuss the 15 most popular QA testing types, and see how they fit into the Software Testing Life Cycle (STLC). 

Categorization of Testing Types

QA testing types can be classified based on several criteria:

• By Application Under Test (AUT) – Categorization based on the type of software (e.g., web, mobile, desktop applications).
• By Application Layer – Grouping based on the three-tier software architecture, including UI testing, backend testing, and API testing.
• By Attribute – Categorization based on specific software properties, such as functional testing, visual testing, or performance testing.
• By Approach – Classification according to the general strategy for testing, such as manual, automated, or AI-driven testing.
• By Granularity – Grouping based on the level and scope of testing, i.e., unit testing and end-to-end testing.
• By Testing Techniques – Classification according to the testing methodology, such as black-box testing, white-box testing, and gray-box testing.

Among these, approach-based categorization is the broadest. For instance, automated testing simply refers to executing tests using automation scripts, and it can be applied to multiple testing types.

15 Different Types of QA Testing

1. Unit Testing

Unit testing is an fundamental practice in software development that includes unit-by-unit (for example, function, method, or module) testing separately. Because units form the overall application, verification of proper behavior in these individual components before bringing them together becomes extremely important.

A unit test typically consists of:

• Test Fixture – Prepares the required environment for executing test cases.
• Test Case – A script verifying the behavior of the unit under test.
• Test Runner – A framework that executes unit tests and generates reports.
• Test Data – Simulated inputs representing real-user interactions.
• Mocking and Stubbing – Substitutes for actual dependencies when real components are unavailable for testing.

2. Integration Testing

Integration testing evaluates how efficiently different software modules interact once they have been individually unit tested successfully. While single modules might behave as anticipated alone, issues might arise when the modules are implemented together.

Integration testing strategies include:

• Big Bang Approach – Integrates all components simultaneously and tests them as a whole.
• Incremental Approach – Integrates components gradually, testing each integration stage.

Types of Incremental Integration Testing:

• Bottom-Up Approach – Starts with smaller modules and progressively integrates larger components.
• Top-Down Approach – Begins with larger modules and gradually incorporates smaller components.
• Sandwich Approach – A hybrid of top-down and bottom-up methods.

3. End-to-End Testing

End-to-End (E2E) testing ensures the overall software application works fine, mimicking actual user experiences.

This helps testers comprehend user experience, discover potential workflow bugs, and authenticate data integrity in systems prior to deployment.

E2E testing, by duplicating live-user scenarios, provides detailed software quality information and enables the identification of defects that cannot be seen under unit or integration testing.

4. Manual Testing

Manual testing requires human testers to review software applications manually without relying on automated tools or test scripts. Testers test the system the way an end user would, detecting bugs, defects, and usability problems affecting the overall user experience.

Even though manual testing is time- and resource-intensive, it is still necessary in some situations when human creativity and intuition are integral. Certain QA testing types call for manual testing, including:

Ad Hoc Testing – A random and unstructured test method in which the testers probe the software without having pre-established test cases, trusting their intuition and experience to find defects.

Exploratory Testing – Also like ad hoc testing, but with greater systematization, enabling testers to discover the software, create test cases during execution, and check for suspected issues.

Usability Testing – Aims to examine the user experience (UX), interface design, and usability. Testers mimic actual user behavior in order to find interface errors and usability issues that automation tools might overlook.

5. Automation Testing (or Automated Testing)

As compared to manual testing, automated testing employs frameworks and tools to run pre-defined test cases automatically. The whole process, right from test creation to running, is managed by automation tools, keeping human intervention at a minimum.

Automating test running helps QA teams improve test accuracy, cut down on manual effort, and enhance efficiency with consistent results while ensuring them. Automation is particularly beneficial for regression testing, performance testing, and large test suites.

6. AI Testing

AI testing augments conventional software testing procedures with the addition of Machine Learning (ML), Natural Language Processing (NLP), and Computer Vision. AI test tools assist in automating sophisticated activities that were earlier intelligently performed by human beings, including data analysis, test planning, and decision-making.

AI-driven testing can:

• Automatically generate test cases based on user behavior data.
• Recommend manual test cases aligned with the test plan.
• Wait for necessary elements to appear on the screen before proceeding with the test.
• Fix broken element locators dynamically and apply updates across subsequent test runs, reducing maintenance costs.

AI-driven QA testing tools help reduce errors, speed up test cycles, and enhance test reliability, making them increasingly valuable in modern software testing.

7. Functional Testing

Functional testing ensures that an application’s features work as intended by validating them against specified requirements. This type of testing can be conducted manually or through automation.

Examples of functional test cases include:

• Verifying successful login using valid credentials.
• Testing login behavior with incorrect credentials.
• Checking if the product search function retrieves relevant results.
• Ensuring backend processes work as expected.

Functional testing is critical to ensuring that core functionalities perform seamlessly before an application is deployed.

8. Visual Testing

Visual testing focuses on verifying the user interface (UI) and visual elements of an application. It ensures that graphical components, layouts, and design elements appear correctly across different devices and resolutions.

Key aspects evaluated in visual testing include:

• Size, width, and length of UI elements.
• Element positioning and alignment.
• Visibility and readability of text and UI components.
• Consistency across different screen resolutions.

Traditional visual testing requires testers to manually inspect the UI. However, automated visual testing tools use a screenshot comparison approach, identifying even minor pixel differences between expected and actual UI displays.

To address false positives caused by dynamic elements (e.g., time, dates, or cart updates on eCommerce platforms), AI-augmented visual testing tools can distinguish between genuine UI defects and expected visual changes.

9. Performance Testing

Performance testing analyzes the performance of a software application under various conditions, assessing speed, stability, scalability, and resource consumption.

There are some subtypes of performance testing, including:

• Load Testing – Mimics normal and peak usage to test how response times and system performance are impacted.
• Stress Testing – Drives an application past its limits to pinpoint performance bottlenecks and establish its breaking point. Findings from stress testing assist in optimizing infrastructure and resource allocation.

Performance testing ensures that an application can respond to real-world usage without delays, crashes, or slowdowns, which is why it is an integral part of the software development cycle.

10. Regression Testing

Regression testing is conducted after code changes to validate that the new updates have not introduced unwanted bugs. Because changes in one section of the application can have an unintended impact on other features, QA teams keep a repository of regression test cases for key functionalities.

Each time there is a code update, these test cases are re-run in order to conserve time and achieve optimum test efficiency, keeping the unpleasant surprises of unexpected software defects from being released.

11. Compatibility Testing

Compatibility testing is done to ensure that an application of software functions as expected in multiple devices, browsers, operating systems, and environments. This testing guarantees that users get a uniform experience irrespective of their system configuration.

The various ranges of compatibility testing are:

• Cross-browser testing – Ensuring functionality in diverse web browsers.
• Cross-device testing – The app working perfectly across devices (desktops, tablets, smartphones).
• Cross-platform testing – Verifying compatibility among multiple operating systems (macOS, Windows, Linux, Android, iOS).

Compatibility testing is key in contemporary software development, particularly in a scenario where customers view applications on many devices and platforms.

12. Accessibility Testing

Accessibility testing determines whether a software program, web application, or digital product is accessible to users with disabilities or impairments. The aim is to recognize and eliminate barriers that would hinder some users from using the system efficiently.

Some of the most important things tested in accessibility testing are:

• Keyboard navigation – That users can interact with the system without a mouse, by using only the keyboard.
• Screen reader support – Confirming that visually impaired users are able to navigate the interface with screen reader software.
• Color contrast – Ensuring that text and graphics have sufficient contrast for color blind or low vision users.
• Alt text for images – Providing descriptive alternative text for images to aid visually impaired users.
• Multimedia accessibility – Validation to see if captions, subtitles, and transcripts are available for audio/video material.

Making sure that digital content is accessible is not merely a best practice—it is mandatory under several pieces of legislation, including WCAG (Web Content Accessibility Guidelines) and ADA (Americans with Disabilities Act).

13. Smoke Testing & Sanity Testing

Smoke Testing and Sanity Testing are quick assessments performed to determine if an application’s basic functionality is stable before conducting deeper testing.

Comparison: Smoke Testing vs. Sanity Testing

Objective:

• Smoke Testing: Verifies critical functionalities.
• Sanity Testing: Validates recent changes or bug fixes.

Scope:

• Smoke Testing: Covers broad, major functionalities.
• Sanity Testing: Limited, focusing on specific areas affected by updates.

Depth:

• Smoke Testing: Shallow, checking overall system stability.
• Sanity Testing: More detailed, but still not full regression testing.

Purpose:

• Smoke Testing: Identifies major blockers that could prevent further testing.
• Sanity Testing: Ensures recent bug fixes or updates have not introduced new defects.

Execution Time:

• Smoke Testing: Quick, executed after each new build.
• Sanity Testing: Quick, performed after small releases or bug fixes.

Outcome:

• Smoke Testing: A pass indicates that core functionalities work.
• Sanity Testing: A pass confirms that recent changes are stable.

Failure Handling:

• Smoke Testing: If it fails, further investigation is required before detailed testing.
• Sanity Testing: If it fails, developers must resolve the issues before a full regression test.

In short, smoke testing is performed before deeper functional testing, while sanity testing is a subset of regression testing that focuses on recent modifications.

14. White Box & Black Box Testing

White Box Testing and Black Box Testing differ based on the internal software structure familiar to the tester.

• White Box Testing – Deals with testing internal code for testing logic, structure, and security. It is performed mostly by developers or coders turned testers.
• Black Box Testing – Seeks to validate functionality without knowledge of the internal implementation. The tester executes the software in the same manner as an end user, ensuring expected outcome without inspecting the code itself.

Both testing approaches are significant in ensuring proof of software reliability, security, and functionality.

15. Testing for Different Kinds of Applications

Software applications are of different kinds, and each has its own testing methodology. The most common kinds of Application Under Test (AUT) testing are:

• Web Testing – Web application testing on browsers, operating systems, and network environments.
• Desktop Testing – Testing desktop applications on Windows, macOS, or Linux desktops for performance, compatibility, and security.
• API Testing – Testing computer software application programming interfaces (APIs) to act as they should, to validate proper communication among computer software entities.
• Mobile Testing – Testing mobile app functionality on different devices, screen resolutions, operating systems, and network conditions.

Every AUT comes with some problems, which demand particular testing strategies to provide best performance, security, and satisfaction to the user.

Each AUT has some challenges, which require specific testing methods to deliver optimal performance, security, and user satisfaction.

Final Thoughts

Grasping various types of QA testing is essential for high-quality software development. All types of testing have a special function to determine bugs, usability problems, performance bottlenecks, and security threats.

QA teams can produce stable, stable, and usable software on various platforms using manual, automated, AI-based, and functional testing methods.