Real Device Testing vs Emulators: Striking the Right Balance

In software development, one of the most critical challenges is verifying the seamless operation of applications on a myriad of different devices, operating systems, user scenarios, and connectivity conditions. This can be especially true for web and mobile apps, where today’s users expect extremely smooth experiences. To do this, developers use testing approaches such as real device testing and emulators to test application functionality, performance and accessibility. Both methods have their pros and cons, and striking the right balance between the two is the secret to shipping good, inclusive software. 

This post delves deeper into real device testing and emulators, gives the pros and cons of each and explains the best ways to use both to achieve the best tests.

What is Real Device Testing?

Device testing is the act of sending an app to a real device (e.g., smartphone, tablet, laptop, or desktop) in order to assess the performance, user experience (UI), or compatibility. This methodology validates the application in a real environment, taking hardware differences, OS versions, network dynamicity, and user behaviors into consideration. Testing on real devices is done either manually or by running the test scripts on tools such as Selenium, Appium or cloud solutions like LambdaTest.

What are Emulators?

Emulators (and their siblings, simulators) are software programs that do the work of a device but on, and as part of, a computer. Emulators simulate the OS and hardware of the target device type and enable developers to test applications without requiring the actual hardware. Some well-known emulators are, for example, the Android Emulator (replacing the old AVD Manager, a tool to create new AVDs, the Android Virtual Devices), and the iOS Simulator (replacing the old iPhone Simulator, only for iPhone development).

Key Differences

• Environment: Depending on the emulator used, both run in a virtual environment — the real device uses real hardware.
• Accuracy: While a real device delivers real-world results, an emulator might simulate some symptoms.
• Cost and accessibility: The real devices need investment in hardware or cloud service, while emulators are mostly free or cheap.
• Scope: Real devices behave as real-world devices, such as battery consumption or network latency, and emulators concentrate on testing at the software level.

The Pros and Cons of Real Device Testing

Benefits

• Real-World Accuracy: Actual user settings and device characteristics, such as hardware capabilities, sensor interferences, and network environment (e.g., variation in network delay), are captured. This way, things such as app crashes when low memory, or an erratic touch response, are identified.
• Complete Set of Tests: Real devices support full device-specific features like camera feature checking, push notifications or biometric checking, which is not possible with emulators or simulators.
• Accessibility Testing: This is vital for inclusive web and mobile development, so that even users with disabilities (for instance, using screen readers, or adaptive input devices) get to see how they experience the app in the real world.
• Network and Performance Reality: Devices introduce factors such as network delay, wireless signal strength, and battery consumption, factors particularly important in eCommerce apps, where performance dictates whether a user remains loyal.

Drawbacks

• Cost: Device lab (which includes iPads, Android devices, tablets…) is expensive. However, despite the convenience, cloud-based real device testing platforms may be encumbered with subscription fees.
• Scalability:  It takes time to test your app on multiple devices, and even more so for large-scale apps or multiple target audiences.
• Maintenance: There is a need for maintenance of those physical devices, updating operating systems, security patches and hardware maintenance becomes another burden task.
• Availability: It can be challenging to access the most current devices or models (such as older versions of Android) for smaller teams.

Use Case

For an eCommerce mobile app, testing on a physical device is essential in the final stage to confirm that the payment gateway checkout works perfectly. Testing on multiple devices (including iPhone 13, Samsung Galaxy S21, and budget Android phones) ensures that payment gateways, touch gestures s and responsive design function perfectly, decreasing cart abandonment resulting from issues specific to a device.

The Pros and Cons of Emulators

Benefits

• Cost-Effective: Emulators are usually free or inexpensive since they are part of development platforms such as Android Studio or Xcode. That would make it accessible to start-ups and small teams.
• Fast and Convenient: With emulators, you can perform widespread testing without acquiring, setting up and maintaining physical devices. Developers can choose between virtual device configurations (such as screen size, OS version, etc.) in seconds.
• Controlled Environment: Emulators mean you can debug your app in a controllable, closed world -no network issues, or low battery issues to affect performance.
• Proto-testing: Using emulators is a perfect option to prototype software and do preliminary development, in order to test the basic app functionality before going to live device testing.

Drawbacks

• Restricted Realism: Emulators may fail to model hardware-specific behaviour, e. g., regarding GPU performance, sensor correctness, or memory restrictions, and generate false positives or false negatives.
• Collateral Inaccessible Testing: emulators are able to mock behaviour for some accessibility features (e.g., screen reader), but not for all features and it may be different compared to real devices.
• Issues with Network Simulation: Emulators can simulate network conditions, but can’t always replicate real-world factors such as spotty connections or carrier idiosyncrasies.
• Platform Specific Limitations: The developer of some emulators, i.e, iOS Simulator is available only on macOS. Hence, the developers of other OS don’t have access to it.

Use Case

Emulators such as the device mode of Chrome DevTools, in the course of creating a web-based eCommerce platform, can test how your responsive design looks for different screen sizes and resolutions. This is a way for developers to easily prototype layouts for tablets, phones, and desktops without access to physical devices.

Real Device Testing VS Emulators: Balancing the Two Sides

A hybrid approach for maximum testing efficiency and comprehensive test coverage is the best strategy and often consists of real device testing complemented by emulators. Here’s how to thread the needle between the two:

Emulate Early in the Development Process

When to Load: During Stage 1, such as prototyping, UI design and unit testing.

Why: Emulators are cheap and iterate fast with them. The likes of Android Emulator or Chrome DevTools can simulate many of devices and screens, helping developers to check for the key functionality and responsive design at an early stage.

For example, suppose you are developing an eCommerce app. In that case, you can test your product listing page’s layout to see how it looks on different OS versions and screen resolutions, and you want to check it out without even actually implementing the logic in the code first.

Transition to Real Devices for Key Areas

When to use: Integration, Performance and Accessibility testing.

Why: Actual devices can often capture fine data like touch sensitivity, battery drain, or screen reader efficacy that emulators likely can’t, which is paramount for eCommerce apps, with user confidence, checkout reliability, and accessibility on the line.

Example: Test the payment flow with actual iOS / Android devices to make sure that the biometric authentication (like Face ID) and payment gateway integration are functioning smoothly.

Use Cloud-Based Real Device Testing-triggered tests from multiple real devices which your app should work

When to Use: For running large, diverse testing on devices, particularly when physical device labs aren’t feasible.

Why: Cloud platforms such as LambdaTest afford us access to thousands of real devices representing a plethora of OS versions, screen sizes, and manufacturers. This way, you are getting complete coverage without having to maintain a device farm.

LambdaTest is a GenAI-Native test orchestration and execution platform that allows you to perform real device testing at scale over 3000 environments.

Sample case: With LambdaTest, one could test an eCommerce store on older Androids (e.g., Android 8.0) and also against the latest iPhones, leveraging global compatibility.

Combine With TestingTool For Accessibility Test

When to Use: During development, for WCAG compliance.

Why: Accessibility is essential to an inclusive eCommerce experience. The features, such as screen reader and keyboard navigation support, can be ensured to be functional via tools like LambdaTest DevTools accessibility extension for Chrome (which we talked about above), which can be added on both emulators and the real device.

Example: Run LambdaTest Accessibility DevTools on an emulator to verify initial WCAG compatibility, then test results on actual devices using assistive features such as VoiceOver or TalkBack.

Prioritize the actual devices for final validation

When to Use: Prior to release or while doing regression testing, or for areas of the product that carry a lot of risk (this could include things like payment systems).

Why: Actual devices give you the most realistic picture of what end-users experience, catching edge cases that emulators don’t, such as those elusive device-specific bugs and performance bottlenecks.

Example: Validate the e-commerce app’s push notification across real devices to ascertain it is being sent and rendered correctly across various manufacturers.

Best Practices for Testing on Real Devices and Emulators

• Determine Testing Goals: Determine what parts of the app (UI, performance, accessibility) need to be tested on real devices vs simulators or emulators. For instance, use emulators for UI layout and real devices for accessibility and performance.
• Build a Device Matrix: Whittle down a list of devices that your demographic uses (such as the most popular iOS and Android devices, or screen sizes). Test on emulators for wide coverage and real devices for edge cases.
• Automate: Leverage automation frameworks such as Appium or Selenium for running your tests across emulators and actual devices, which results in less manual effort and brings more consistency.
• Test Accessibility Early: Ensure your code is accessible by testing it early using LambdaTest Accessibility DevTools within the development and production environments, to catch errors early and validate on real devices.
• Track Real-World Feedback: Keep an eye on user feedback and analytics after launch, and use this information to identify device-specific bugs and their relevance for future testing priorities.
• Maximize Cloud: Adopt cloud-based testing services to scale real device testing, while renting instead of buying devices can strike a balance between the cost and coverage.

Challenges and Solutions

Challenge 1: Cost Management

Issue: Testing on physical devices is costly, especially for smaller teams.

Answer: Emulate for the first shot and the real device for critical functionality or final validation. Services, such as LambdaTest, are cloud-based platforms offering low-cost real devices.

Challenge 2: Fragmentation

Issue: The large number of device-OS combinations (specifically on Android) makes testing everything almost impossible.

Solution: Analyse the most popular devices within your demographics and test those first. Less typical combinations can be emulated.

Issue 3: Web Accessibility. If not accessible to people with disabilities, that’s not inclusive.

Challenges: Being able to provide a consistent development experience for all devices is complicated, as emulators do not always emulate assistive technology.

Solution: Cross-verify emulator-enabled accessibility scans with real device testing through tools like VoiceOver, TalkBack, or the LambdaTest Accessibility DevTools Chrome Extension.

Conclusion

The emulators and real device testing both have their place when it comes to building inclusive eCommerce applications to ensure high quality and user satisfaction. They form cost-effective, flexible bases set for early-level development and wide-ranging coverage with emulators, and for accuracy, accessibility, and real-world performance in testing on real devices. Taking a hybrid approach that leverages simulators for prototyping and early test passes, cloud-based real device testing for scalability, and real devices for final validation can help developers achieve the right balance. 

Tools such as LambdaTest Accessibility DevTools Chrome Extension can help to streamline this process even more, making sure the pages of both environments are WCAG compliant. Finally, when you combine these approaches with clear testing goals and automation, you will build strong, accessible, user-friendly applications that can provide for the broad and varied needs of your audience.