DEV Community

Cover image for Emulators vs. Real Devices For Test Automation: Which Is Better?
Steve Wortham
Steve Wortham

Posted on

Emulators vs. Real Devices For Test Automation: Which Is Better?

With the advancement of technology, testing has also seen improvements in mobile testing solutions.

These solutions are designed to support mobile apps and cross-browser testing of websites on various mobile phones by analyzing the application’s function, behavior, and user interface.

Because there are so many mobile devices, each with its own operating system, hardware configuration, and screen resolution, what works on one device may not work on another.

For mobile testing, there are primarily two types of devices:

Emulators vs. Real Devices For Test Automation: Pros & Cons

Real Devices

Real testing devices are various mobile handset models used to test a website’s or mobile app’s behavior and functions. These are the actual mobile handsets used by the end user.

These tests are carried out by purchasing several mobile handsets running various operating systems, such as Android and iOS, as well as tablets and iPad devices.

Virtual Devices

A virtual device is a program that simulates the mobile device’s real software and hardware. Emulators and simulators are two types of virtual devices used for this purpose.

This is accomplished by translating the target device’s ISA (Instruction Set Architecture) to the computer. It completely replicates your target device’s work and creates a virtual testing environment.

Evolution of Testing: From Real To Virtual Testing Devices

Real device mobile testing has become difficult with the release of over 60 Android phones and 18 iOS versions in 2020. Testing strategies have evolved to virtual devices, whether you are testing the mobile application manually or through automation.

Although results generated on real devices are more accurate, the testing cost is very high because the company must purchase many mobile devices and update them as new devices enter the market.

Virtual testing devices for mobile apps and cross-browser compatibility testing have been introduced to reduce the cost of real-world device testing.

When To Use Emulators Vs. Real Devices For Test Automation?

There are numerous advantages to using emulators and real devices, but the testing strategy is determined by the risk and stage of the application.

The best option for test automation is to use an emulator. If the users’ primary goal is responsiveness, real and virtual testing should be used.

Furthermore, the emulator is significantly less expensive than using a real device. When the main danger is swiping and dragging the application, the emulator may be the best option.

Many organizations prefer to conduct only real-world device testing, which is very expensive. As a result, the general rule is to use emulators for both hardware and software.

When different memory allocations and central processing units are used, an emulator can test the application’s behavior. Emulators are especially useful when testing must be performed under various conditions.

On the other hand, Emulators are more useful when combined with real-world device testing practices.

Pros and Cons of Automating Tests In Emulators

Advantages

  • The most significant advantage of the emulator is the price, which is either free or very low.
  • You only need to download and install the application to start. Emulators are client software that runs locally.
  • They rely on fewer or no real devices and run faster than real devices connected to a local network or the cloud. The emulator is included in the SDK that software developers receive.
  • Mobile emulators with a strong development environment integration provide access to detailed debugging information, which is critical during the development phase. In addition, it enables testers to proceed with the application’s step-by-step debugging on the emulator. Furthermore, there may be instances where mobile emulators provide enormous benefits by simulating difficult-to-replicate scenarios (such as specific GPS coordinates, low battery, and so on) that a real device cannot support.

Disadvantages

  • Even if the testing goes flawlessly, there is no guarantee that the data can be applied to a real device. Instead, it asks which tests must be verified in real-time and which can be trusted on emulators.
  • Also, if the test fails on the emulator, it is critical to determine whether the function should be tested on the mobile device or assumed to be unchanged.
  • Another disadvantage is that the emulators must be run on a PC and connected to a LAN to access the internet.
  • The network is directly connected to the radio interface and the internet while using devices. Different network environments can cause different application behaviors in many cases.
  • Because the mobile device is a phone, network-related events (text messages, incoming calls, etc.) should be tested to assess the application’s impact.
  • And performing these tests with an emulator can be difficult because network quality varies between states, carriers, regions, and countries. Because emulators are connected to the mobile network, they cannot detect the effects on the application.

Pros and Cons of Automating Tests In Real Devices

Advantages

  • Testing on real devices always yields accurate results, with no concerns about false positives or negatives. This type of testing takes place in a live network. It is an essential testing procedure because it is unaffected by network-related events. For example, the entire testing process will be lost if a text message or phone call arrives in the middle of a transaction.
  • Furthermore, network technologies (LTE, HSDPA, WIFI, etc.) can significantly impact the application’s behavior.
  • Real-world device testing is the only way to understand a given device’s user experience, screen size, and CPU factors.
  • Real handset operations can provide the best testing results for service quality. Furthermore, real-world devices make it much easier to detect performance flaws.
    Disadvantages

  • As previously stated, real devices are physical handsets that must be managed appropriately. However, the costs and logistics of acquiring these resources are incredibly high.

  • Another issue is the variety of handsets that must be purchased and which devices must be obtained. Real devices are more challenging to connect to an IDE in the early stages of development than emulators, which can slow down the debugging process.

Disadvantages of Both: Emulators and Real Devices

Image description

Tests that only real devices can perform:

Tests run on real devices can perform network, performance, real OS (with manufacturer’s tweaks), user interaction, and battery consumption tests. This level of complexity is achieved only through a product identical to that of the end user’s, not an emulator.

Network: On varied networks like 2G, 3G, 4G, and under different network conditions like low bandwidth or high latency, app testing can only be conducted using real devices.

Performance: Emulators are not the best for many testing situations, such as circumstances where developers need to test performance over an extended period of time.

Real OS (With Manufacturer’s Tweaks): It is not enough if an app is tested on a single OS version of a device. For the app’s success and positive rating, it has to be tested on a myriad of real devices with different OS versions.

User Interactions: Using physical inputs like Zooming, Pinching, Scrolling are considerably different on touch-screens. Also, sensor inputs such as GPS, proximity sensors, shake, and NFC cannot be simulated.

Battery Consumption: The only way to test an app with varied battery conditions is by using physical devices. Emulators cannot simulate activity under different stages of battery life.

Winning Strategy

Although real-device testing is the best option, emulators can be used in the early stages of the development lifecycle.

Later on, you can move on to real-world devices. With a cloud testing solution provider, you can also scale up your test automation and run tests on as many devices as you need.

Real Device Cloud Testing With TestGrid

You now know the answer to your question: whether to use emulators or real devices for test automation.

Your next step should be to find the right balance of real-device and emulator-based testing while combining and complementing the two approaches with the best cloud testing solution.

Conclusion

For comprehensive test automation, a hybrid approach is often best. Begin with emulators for quick functional testing and use real devices for thorough testing of performance, usability, and device-specific features to ensure a flawless user experience.

Source: This article was originally published at testgrid.io.

Top comments (0)