Cypress vs Puppeteer: What are the differences?

Introduction

Cypress and Puppeteer are both popular automation testing tools used for web application testing. While they serve a similar purpose, there are key differences between the two.

1. Architecture: Cypress runs directly in the browser and executes commands while the page is rendering, which provides real-time feedback and control over the application. On the other hand, Puppeteer uses a separate Node.js process and communicates with the browser via the DevTools Protocol, making it suitable for non-rendering tasks as well.

2. User Interface Testing: Cypress is primarily focused on end-to-end testing, providing features specifically tailored for testing user interfaces. It comes with a rich set of assertions and automatic waiting for network requests and DOM modifications. Puppeteer, however, is more flexible and can be used for testing not only the user interface but also automating tasks such as scraping, generating screenshots, or automating form filling.

3. Browser Compatibility: Cypress only supports Chrome-based browsers, limiting its cross-browser testing capabilities. On the other hand, Puppeteer can control Chrome, Firefox, and other browsers through the use of the puppeteer-firefox library. This gives Puppeteer an advantage when it comes to testing on multiple browsers.

4. Speed of Execution: Cypress runs tests in the same run loop as the application, allowing for faster execution as it can anticipate the application state and skip unnecessary waiting time. Puppeteer, being an outside-in approach, may have a slightly slower execution time as it needs to interact with the browser via the DevTools Protocol.

5. Debugging Capabilities: Cypress provides an interactive test runner that allows developers to debug tests in real-time using built-in tools such as the Cypress Command Log or the browser's DevTools. This makes it easier to track down and fix issues. Puppeteer, while it can be integrated with external debugging tools, does not have the same level of built-in support for test debugging.

6. Vendor Support and Community: Cypress is an open-source project backed by a dedicated team and has gained significant traction in the testing community. It has a strong community support and regular updates from the maintainers. Puppeteer, on the other hand, is maintained by the Chrome team and has the advantage of being part of the Google Chrome ecosystem. It also has a large community and is well-supported.

In Summary, while both Cypress and Puppeteer serve the purpose of automation testing, Cypress is more focused on user interface testing with a Chrome-only browser support, faster execution speed, and built-in debugging capabilities. Puppeteer, on the other hand, offers more flexibility with multi-browser support, non-rendering tasks automation, and the advantage of being maintained by the Chrome team.