End-to-End Testing vs Regression Testing

Software testing is an essential aspect of software development. There are many different types of software tests that can be conducted and it is important to choose the right tests and test management tools for best results. Two common approaches to software testing are end-to-end testing and regression testing.

End-to-end testing involves testing the application from start to finish whereas regression testing means retesting the application functionalities after changes are implemented. In agile software development, both techniques are important and come with their own set of advantages and disadvantages. Both types of testing are made easier with the implementation of test case management best practices and a test management tool like Testworthy.

The software testing method chosen depends on the ultimate goals of the tester. Let’s have a look at both software testing techniques in more detail.

End-to-End Testing

End-to-end testing, as the name suggests, involves testing the full application flow, functionality and process from start to end. It validates the software system and checks that the various layers within the application are all working correctly, ensuring system dependencies and testing interaction of different components.

End-to-end testing is conducted from user perspective, testing the entire user experience to confirm that processes work as intended. It is the comprehensive testing of the whole system to check performance in a post-release stage and find any compatibility or integration issues. It is similar to User Acceptance Testing (UAT) because it tests user experience but unlike UAT, it is performed by testing professionals rather than users. Conducted in a simulated production environment, end-to-end testing ensures that end user functionality is effective, workflows and navigation are seamless and the software meets end user and client requirements.

There are two major types of end-to-end testing: Horizontal and Vertical.

Horizontal vs Vertical End-to-End Testing

Horizontal end-to-end testing simulates and tests the user’s journey from beginning to end, evaluating workflows across various systems and applications. It is done from user perspective so users can use the app and its features with ease and bugs can be identified before reaching production. Vertical end-to-end testing means testing each layer in an application’s architecture (for example, UI, API, Security etc.) in a sequential order. It tests software across various layers from top to bottom. Horizontal end-to-end testing is a black-box testing technique that tests outputs whereas vertical end-to-end testing is similar to white-box testing and tests the inner workings of the system.

Both horizontal and vertical end-to-end testing can be made more effective with good test case management and use of test management tools like Testworthy.

When coupled with good test case management, end-to-end testing can offer many benefits.

Benefits of End-to-end testing:

  • • Ensures stability
  • • Helps identify problems in integrations or other areas.
  • • Improves test coverage
  • • Ensures that all layers of the app are working and reliable
  • • Enhances customer experiences by testing user experience from start to finish
  • • Covers business processes and logic
  • • Verifies system dependencies and ensures that all components work together effectively.

End-to-end testing can be extensive and complex. This is because it is difficult to predict exactly how customers will interact with an application. Replicating all user navigations, scenarios and interactions is not possible and can quickly become complex and time-consuming. Another challenge posed by end-to-end testing is that testing is done near the end stages of software completion i.e., in production environment. Complete test environment setup is required for testing.

Due to the complexity, end-to-end testing should be limited to key areas. It is better to utilize end-to-end testing to test critical business workflows and processes and reserve lower effort tests for less important areas. Whatever the scope of end-to-end testing may be, testing efforts can be simplified with the aid of test management tools and test case management strategies.

software testing + regression testing + end-to-end testing

Regression Testing

After software undergoes some change or update it is important to retest the system to make sure that the change did not cause any disturbance in functionality, compatibility or performance elsewhere. This is where regression testing comes in. Whenever features are added, removed or modified, software is updated, bugs are resolved or any other change in code takes place - regression tests are run to recheck functionality of unchanged features and verify that the changes are not causing any problems in existing code.

Regression tests can take place at any software testing level. Regression tests may involve re-running old tests or creation of new tests to check software performance. The scope of regression testing varies and existing test cases may be re-run, either partially or entirely. In some cases, only tests for new features and functionalities are conducted. At other times, new changes are tested along with retesting of old unchanged parts or modules which are likely to be impacted. In most cases, regression testing is not about covering every test scenario but rather covering the most critical and high-priority areas.

When software increases in complexity, test suites and test cases for regression testing expand. As regression cycle becomes overly complex and time-consuming, automation becomes essential. Automation can help cope with the large scope of testing and increase test coverage while saving time. Along with the right test automation tools, selection of a good test management tool also becomes important to aid in test case management.


To summarize, end-to-end testing tests workflows and layers of the entire application, whereas regression testing re-tests functionalities after software updates.

In agile software development, both end-to-end testing and regression testing are essential. What needs to be decided is how extensive the scope for each type of testing should be and how much time and effort is dedicated to each software testing type. This decision can be dependent on various factors such as project or business requirements, priorities and available budget.

Software testing is made easier with test management tools like Testworthy. Testworthy is a one-stop test case management solution that enables teams to collaborate and conduct effective testing. Sign up for a free trial today.


End-to-end testing is a type of software testing technique that tests software from start to end. This includes horizontal end-to-end testing, which involves testing a user’s journey and workflows, as well as vertical testing which includes testing the various layers, systems and sub-systems of an application.
Regression testing is a type of software testing which is conducted every time a software is updated or modified. The purpose of regression testing is to ensure that any new updates and modifications in code do not impact existing functionalities in the software.
Regression testing can take place at any testing level and involves re-running old test cases. It can occur more frequently than end-to-end testing. End-to-end testing is usually done at higher testing levels to test the process completely and thoroughly. It involves creating new test scenarios and test cases. Regression tests take place in pre-production environment whereas end-to-end testing is conducted in production environment.
End-to-end testing and regression testing are both important aspects of software testing. Both are inter-linked as regression testing can include end-to-end testing as well. On the other hand, end-to-end testing also involves both regression testing and new feature testing.

Both end-to-end testing and regression testing can be handled more efficiently with the help of test management tools like Testworthy. In agile software development, test automation for both processes can do wonders in increasing test coverage and managing an increasingly large test suite.