An E2E test (end-to-end test) checks an application from the user’s point of view, across all layers. Choosing the right E2E testing framework starts with defining your own requirements clearly, before you compare tools. Teams that prioritize Safari support, execution speed or debugging convenience will end up with different answers. Among the frameworks compared, including Cypress, Playwright, Selenium, TestCafe and Nightwatch, Playwright stood out for its speed and low resource usage.
Key Takeaways
- Introducing a testing framework without defining concrete requirements first risks blind spots: Mesut Durukal found out too late that the tool already in use didn’t support Safari at all.
- The choice between Cypress, Playwright, Selenium, TestCafe and Nightwatch depends on the project’s goals. Playwright wins on execution speed and small Docker images, Cypress on its built-in dashboard and its own debugger.
- Not every framework requirement can be put into numbers. Speed, for example, has no fixed threshold, but it still has to be named and prioritized as a criterion.
- If you build your automation code without duplication and with reusable helper classes from the start, you can switch frameworks later without rewriting all your test cases.
- Choosing a tool is not a one-time decision. Frameworks keep evolving, so it pays to review existing decisions regularly against new requirements and alternatives.
Why Your Choice of E2E Testing Framework Determines Test Coverage
Your E2E testing framework decides what you can test in the first place. Get the choice wrong, and you won’t cover cases that are central to your product. Mesut Durukal learned this when he joined a running project and inherited the tool that had already been chosen.
Test automation is part of quality assurance because a large number of test cases simply can’t be handled manually. That doesn’t mean any tool will do. The choice of tool and the way the environment is set up define the limits of what automation can achieve.
In Mesut’s case, it came down to a missing browser. The existing tool couldn’t run test cases in Safari. In the region where Mesut was testing, most of the traffic came from iOS and macOS devices, which means Safari. The browser used by most of the users was completely missing from the test coverage.
Define Your Requirements Before You Compare Tools
Start with a list of the features your test cases actually need, not with the tool. Many teams do the opposite: they buy something, try it out and discover later that it doesn’t fit.
Mesut built his list of requirements from two sources. The first was his own experience with the application at hand: which attributes appear on the web pages, are there iframes, do interactions open new tabs or pages? The second was conversations with the product team and the developers, to fill in gaps and capture known risks.
For a fairly simple web application with a few pages, text fields and buttons, the list stayed short. Still, there were clear must-haves:
- Test execution in Safari, because that’s where most of the traffic came from
- Support for device emulators, to simulate mobile views right in the browser instead of on real devices
- The ability to modify requests, to trigger different use cases on purpose
Not every requirement can be defined strictly. For execution speed, there was no fixed target like “under ten seconds.” The framework should run test cases as fast as possible, but the threshold remained a gray area. Soft criteria like this belong on the list too, as long as everyone knows they have no hard limit.
What a Structured Comparison of E2E Testing Tools Looks Like
Put together the frameworks that are widely used in the community and rate their strengths and weaknesses against your list of requirements. Mesut picked four or five of the most downloaded frameworks on npm, the leading E2E testing tools at the time: Cypress, Playwright, Selenium (one of the oldest), TestCafe and Nightwatch.
So which is the best E2E testing framework? There isn’t one that wins across the board. Each has different strengths and different weaknesses. What counts is which feature has the highest priority for your project. For Mesut, Safari support came first, and that one criterion shifted the result.
This overview sums up what stood out in the comparison:
| Framework | Strength | Weakness |
|---|---|---|
| Cypress | Built-in dashboard and its own runner, results including duration and flakiness with no extra effort, debugging in a separate window | No test execution in Safari at the time (WebKit only in beta) |
| Playwright | Three to four times faster than the alternatives, small Docker image, light on resources in the pipeline | No notable weaknesses in the project |
| Nightwatch | Very readable, simple code | Weaker community support, open tickets, gaps in the documentation |
| Selenium | Highly customizable, you can build your own solution on top of it | (Not evaluated in detail in the comparison) |
For Cypress, Mesut highlighted the reporting. After a run, all results land in the dashboard automatically (now called Cypress Cloud), including the execution time per test case and flags for flaky tests. With other tools, you have to build that kind of reporting yourself.
Playwright won on speed. The small Docker image loads quickly in the pipeline, and test runs were noticeably faster than with the alternatives.
Put the Weaknesses on the Table
Every framework has its catch, and that catch belongs in the evaluation. At the time of the comparison, Cypress couldn’t run tests in Safari. Beta versions for WebKit, the engine behind Safari, came out later, but back then this ruled Cypress out for Mesut’s requirement.
With Nightwatch, the problem was less the code than the ecosystem. As an open-source project without a big company or community behind it, tickets stayed open, and some problems had no clear solution. Cypress is older than Playwright and therefore has more community material, which makes troubleshooting easier.
“I can’t say that this tool is the best. Each one has different strengths and different weaknesses. The most important thing is to find out which feature matters most to you.”
(Mesut Durukal)
Architecture Decides How Costly a Framework Switch Will Be
A reusable architecture keeps the cost of switching from one framework to another low. If shared operations are cleanly encapsulated, a tool change doesn’t touch them.
When Mesut switched, he didn’t delete the test cases. He converted them. Deleting them would have meant they were redundant, and they weren’t. One decision he’d made from the start kept the conversion effort small: avoid duplication.
Login shows the principle. Almost every test case needs to log in. If the login logic sits directly in the spec files, you have to change it in every single file when you switch. If it lives in a helper class in a plain JavaScript file, it stays untouched when you move from Cypress to Playwright. The functions are then just ordinary code in a programming language, reusable no matter which framework you use.
Machine learning platforms can take over part of the conversion. You feed them the spec files and let them convert them. The accuracy isn’t good enough to automate the whole job, but it gives you a starting point and cuts down the manual work.
Your Tool Decision Is Never Final
Check regularly whether your end-to-end framework still fits your requirements. A decision once made is not the end of the story. Requirements change, and the frameworks themselves keep evolving, sometimes with new versions almost daily.
That leaves you with two tasks side by side. Before choosing, you work out which feature matters most to you and whether a framework delivers it. Afterwards, you keep an eye on whether the tool you chose will still hold up in the future. There is always room for improvement, so it’s worth keeping that question open.
Frequently Asked Questions
What’s the most common reason for failure when selecting an end-to-end testing framework?
Most often, it’s because a tool is purchased and tested first, and only then are the requirements brought to the table. Mesut Durukal took over a pre-selected framework in an ongoing project and realized too late that it didn’t support Safari. In his region, the majority of traffic came from iOS and macOS devices. This meant that Safari was completely excluded from the test coverage.
Where do I get the requirements for a test automation framework?
From two sources. The first is your own experience with the specific application: What elements appear on the pages? Are there iframes? Do interactions open new tabs? The second is discussions with the product team and developers to fill in gaps and account for known risks. Typical must-have criteria include browser coverage, device emulators, and the ability to customize requests.
How do you handle criteria that can’t be quantified?
They still belong on the requirements list, but with the understanding that they don’t have hard-and-fast limits. For execution speed, there was no specific requirement in the project described, such as “under ten seconds.” The only requirement was: as fast as possible. The key is to consciously identify such a soft criterion and rank it in the prioritization process, rather than tacitly omitting it.
Is there a single framework that’s best for all projects?
No. Every framework has different strengths and weaknesses, and the one that’s right depends on the feature with the highest priority in your specific project. In the comparison described, Safari support was at the top of the list, and it was precisely this one criterion that tipped the scales. Those who prioritize debugging convenience or reporting features instead will arrive at a different choice.
What distinguishes Cypress and Playwright in practice?
Cypress comes with a dashboard and its own runner: results (including execution time per test case and notes on unstable cases) appear there without any extra effort, and debugging runs in its own window. In the comparison, Playwright was three to four times faster than the alternatives and loads quickly into the pipeline with a small Docker image. At the time, Cypress did not support execution in Safari; WebKit was only available as a beta.
Why can a weak community become a deal-breaker for a framework?
Because the problem then lies not in the code, but in the ecosystem. With Nightwatch, an open-source project without a major company behind it, open tickets piled up, the documentation was incomplete, and no clear solution could be found for some issues. Older frameworks have more resources available in the community, which makes debugging noticeably easier.
How do you keep the effort to a minimum if you want to switch test frameworks later?
By structuring the automation code without duplicates from the very beginning. The login is required in almost every test case. If its logic is contained in the spec files, it must be changed in every single file when switching frameworks. If it’s located in a helper class within a pure JavaScript file, it remains unchanged when switching from Cypress to Playwright.
Can test cases be automatically transferred from one framework to another?
To some extent. Machine learning platforms can convert spec files and reduce manual effort, but their accuracy isn’t sufficient for full automation. They provide a foundation that needs to be refined. In the project described, the existing test cases were therefore converted rather than deleted: Deleting them would have implied that they were redundant.
