Emulator vs Simulator vs Real Device

Every developer knows that you need to thoroughly test a mobile app before sending it out. The challenge lies in figuring out what testing environments work best.

How effective is an emulator vs simulator – and what’s the difference between the two?

How much of the testing should be on real devices?

And how does one manage the costs and timelines for it all?

We know it can feel confusing, and we’re here to show you that it doesn’t have to be. In this piece, we’ll answer all your questions about mobile testing on emulators, simulators, and real devices, and how to choose the right option for your app.

Option 1: Emulators

What is an emulator, and how does it work?

An emulator is essentially a virtual copy of a mobile device on your computer. It replicates hardware behaviors such as CPU, device storage, and memory, along with the software environment.

It’s a great way for you to test how your app interacts with the device hardware, OS, and existing apps without needing an actual mobile unit.

Ideal use cases for emulator testing include:

• Testing across different OS versions

• Testing across different screen sizes and resolutions

• Testing your app’s basic features and screen layout/navigation during the early stages of development

• Debugging your app in a controlled environment without worrying about things like battery or network issues

Pros of using an emulator

• In-built debugging tools to help you easily find and fix issues

• Can mimic a device’s hardware and software on a workstation

• Ability to simulate different OS versions with high configurability

• Ability to try out risky experiments without the worry of damaging your device

• Budget-friendly way to test across multiple devices without actually buying them

Cons of using an emulator

• Slower performance than a real device, especially for resource-intensive apps

• Limited ability to simulate hardware features such as cameras, GPS, or biometric sensors

• Difficulty with replicating real-world conditions like touch responsiveness or behavior under edge cases

Tips to get started with emulator testing

• Choose the right emulator for the job. Android Studio and Xcode provide reliable options for Android and iOS respectively.

• Make a note of the features you’ll have to test elsewhere, such as camera-dependent features on a real device.

• Run your tests for functionality and compatibility and debug any issues on the spot.

• Configure the emulator for each of the device versions you’re targeting.

Option 2: Simulators

What is a simulator, and how does it work?

A simulator is a tool that virtually replicates a device’s software environment to help you test your app’s functionality and user interface, just as if it were on a real device.

The big difference between simulator vs emulator is that a simulator is software-specific, and doesn’t mimic any hardware-level interactions. So simulator testing is mainly about the app’s behaviour itself, and not how it interacts with the rest of the device.

Ideal use cases for a simulator include:

• Testing early during rapid iterations, as it’s faster than an emulator

• Validating app UI, design elements, and basic navigation logic

• Testing in an iOS environment with Xcode

Pros of using a simulator

• Lightweight and easy to set up

• No need to buy physical devices

• Best for testing layouts, animations, and other aspects of app UI

• Faster to run than an emulator, since it doesn’t replicate hardware

Cons of using a simulator

• Inability to test features that rely on hardware

• Limited performance testing for real-world conditions or on lower-end devices

• Largely tied to a specific platform, eg Xcode only supporting iOS and not Android, making investment in multiple platforms necessary

Tips to get started with simulator testing

• Set up the different resolutions, screen sizes, and OS versions and then run your tests.

• Install the right tool (typically Xcode for iOS), and remember that Android app testing relies on emulators.

• With both simulator and emulator testing, you’ll need to schedule time and a budget for testing on real devices.

Option 3: Real Devices

What is a real device, and how does it work?

A real device is just that – an actual mobile device, like a smartphone or a tablet, that you run tests on. A real device lets you interact with the app in the exact same way an actual user would, giving you the most accurate results in terms of usability and performance.

That’s why, regardless of whether you go for emulator vs simulator in mobile app testing, you’ll need to devote some testing time to real devices.

Ideal use cases for real device testing include:

• Assessing how the app handles real-world conditions like battery consumption or memory constraints

• User experience elements like touch responsiveness that emulator and simulator testing cannot mimic

• Testing across different device models, brands, screen sizes, and so on

• Testing hardware-dependent features in your app

Pros of using real devices

• Most accurate depiction of app behaviour in real-life contexts

• Only option for testing features connected to hardware like GPS or sensors

• Authentic feedback on UX elements like touch, gestures, animations, and so on

• No limitations due to differences between the real world and virtual emulator/simulator environments

Cons of using real devices

• Can be quite costly to build and maintain an up-to-date device lab

• High costs of charging, updating, and replacing devices

• Time-consuming to test across so many devices

• Difficult to cover all possible configurations

Tips to get started with real device testing

• Start by setting up a device lab with the device versions most commonly used by your target audience.

• Consider using real device testing platforms like TestGrid to access real devices remotely at a lower cost.

• Invest in real devices for final validation of the app once you’re done testing on emulators and simulators.

• Prioritize testing hardware-specific features and everyday usage scenarios on your real devices.

Emulator vs Simulator vs Real Device: A Tabular Comparison

Here’s a breakdown of how emulators, simulators and real devices compare against each other.

Advantages of Combining All Three Options

Instead of getting hung up on the difference between emulator and simulator in mobile testing, we recommend using a smart combination of all three options to cover all the bases of testing your app. Here’s how to do it.

1. Start with emulators and simulators

When you’re just starting out with app development, these two are cost-effective and efficient ways to test your functionality and OS issues. Simulators are ideal for checking UI-related features, while emulators are great for debugging issues related to the operating system.

2. Move to real devices for the critical features

As you move towards the final development stages, bring in real devices to test app features that interact with device hardware like cameras or sensors.

Real device testing also lets you see how the app performs under various network or battery conditions and do a final sanity check on how the end user will experience the app.

3. Use device clouds to optimize your costs

You don’t necessarily have to build your own device labs. Cloud-based testing platforms allow simultaneous remote testing across a wide range of device configurations and operating systems. This significantly brings down your testing costs while still giving you the advantage of real device access.

Final thoughts

Let’s circle back to the original question – how to choose between simulator vs emulator in mobile testing? As is clear by now, there’s no single best option.

Emulators, simulators, and real devices all have their role to play in mobile app testing, with the former two offering speed and scalability and the latter offering the crucial real-world validation.

No matter what your app’s purpose is, you’ll benefit from a judicious mix of all three options to optimize its performance and give users a flawless and enjoyable experience. Give this approach a try – your audience will thank you.

Source: This blog was originally published at https://testgrid.io/blog/emulator-vs-simulator-vs-real-device/