# Testing Develop and run tests to detect logic failures, UI problems, and performance regressions. ## Overview An important part of software development is testing your code. To catch issues early and deliver the highest quality products, use the frameworks and features Xcode provides to develop tests, understand code coverage, and evaluate your test results. Xcode 16 and later includes , a new testing framework you can use to write unit tests that takes advantage of the powerful and expressive language capabilities of Swift with output that is expressive and actionable. Xcode continues to include to facilitate writing UI tests that control your app’s UI using . A good testing strategy combines multiple types of tests, to maximize the benefits of each. Aim for a “pyramid” distribution of tests, as shown in the figure below. Include a large number of fast, well-isolated unit tests to cover your app’s logic, a smaller number of integration tests to demonstrate that smaller parts connect together properly, and UI tests to assert the correct behavior of common use cases.  UI tests are the ultimate indicator your app works the way you expect, but they take longer to run than other kinds of tests. There are various app variables that can introduce a failure in the same UI test. The test pyramid balances high-fidelity tests that demonstrate that people can complete their tasks, with tightly-focused tests that give you fast feedback about the correctness of your app’s logic and the impact of changes you make. In addition to the test pyramid, write performance tests to provide regression coverage of performance-critical regions of code. To learn about the process of identifying performance-critical code, see [Improving your app’s performance](/documentation/Xcode/improving-your-app-s-performance). ## Topics ### Test development [Adding tests to your Xcode project](/documentation/Xcode/adding-tests-to-your-xcode-project) Include test targets that build code to test the logic in your functions, check for integration issues, automate UI workflows, and measure performance. [Updating your existing codebase to accommodate unit tests](/documentation/Xcode/updating-your-existing-codebase-to-accommodate-unit-tests) Remove coupling between components to increase test coverage and reliability. [Determining how much code your tests cover](/documentation/Xcode/determining-how-much-code-your-tests-cover) Use code coverage to focus new test development on areas that lack adequate testing. [Improving code assessment by organizing tests into test plans](/documentation/Xcode/organizing-tests-to-improve-feedback) Control the information you receive from your tests at different stages in the software engineering process by creating and configuring test plans. ### Execution and results [Running tests and interpreting results](/documentation/Xcode/running-tests-and-interpreting-results) Determine whether your project’s code behaves as you expect by running tests and understanding the results. ### Performance tests [Writing and running performance tests](/documentation/Xcode/writing-and-running-performance-tests) Repeatably gather metrics on the performance of your code. ### Location [Simulating location in tests](/documentation/Xcode/simulating-location-in-tests) Improve test reliability and coverage when working with location-based code. ### StoreKit [Setting up StoreKit Testing in Xcode](/documentation/Xcode/setting-up-storekit-testing-in-xcode) Prepare your test environment to test in-app purchases with data you configure locally. [Testing in-app purchases with StoreKit transaction manager in Xcode](/documentation/Xcode/testing-in-app-purchases-with-storeKit-transaction-manager-in-code) Use the transaction manager within Xcode to test in-app purchases without requiring a connection to App Store servers. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)