Emulator vs Simulator vs Real Device: A Detailed Comparison

Mobile testing is the process of evaluating whether an application created for portable devices satisfies particular functional, visual, performance, and security  requirements. There are 2 main types of devices for testing: real devices and virtual devices (emulators and simulators). Even though emulators and simulators are both virtual environments, the main difference is that simulators only mimic the software features, while emulators cover both software and hardware.

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The process of mobile testing involves spotting bugs in a mobile application and fixing them – ranging from identifying sign-up issues, checking the payment process, or finding glitches in navigation before it slips into production. This can be done through manual mobile testing or with automation, and utilizing the right mobile testing strategy helps meet all quality and usability requirements.


Among the elements necessary for a seamless testing process is the selection of the right testing devices. Hence, it is very important to understand the similarities and differences between these types of mobile testing devices. This blog will clearly compare all three types: emulator vs simulator vs real device, thereby suggesting the best practices for choosing the right device based on your distinctive needs.

What is an Emulator?

Emulators are virtual testing software on a computer that imitates both the software and hardware configuration of a mobile device or another computer. It works on an ISA (Instruction Set Architecture), which is written in machine language that the processor understands. The emulator imitates the target (mobile device) processor by translating its ISA into the one used by the system through the binary translation process. This helps the computer create a reliable virtual testing environment.


Some examples of widely used emulators for testing are Android emulators, iPhone emulators, etc. Emulators are also entering the cloud mobile testing field with the availability of cloud-based Android devices.


Emulator examples
Figure - Example of Android emulator 

What is a Simulator?

Simulators are virtual testing software built for different operating systems for a specific purpose, not representing the hardware. The iOS simulator imitates iOS and runs the required application within the environment by taking charge of the computer’s operating system.


Simulator examples
Figure - a mobile simulator running an iPhone 12 Pro Max

Besides, iOS simulators work on macOS only because the simulator needs Apple’s native Cocoa API (a library of frameworks to handle GUI, runtime, and other operations). Therefore, testers must use either MacBook or virtualized macOS on their systems. Also, these simulators cannot imitate hardware, and some functionalities (battery state, motion sensor, and cellular interrupts) cannot be tested with it.

Emulator vs Simulator: A Comparison

1. Emulator vs Simulator: Similarities

In one way or another, emulators and simulators are quite similar to each other, sharing the mutual goal of creating virtual environments on a desktop where testers can run real-life test cases flexibly and easily, helping QA teams understand how the software performs in different scenarios. 

Whether it’s simulating a smartphone’s touch gestures, or emulating particular hardware details of a gaming application, these virtual performers enable a comprehensive testing process, ensuring the responsiveness of the software with user interaction.

a. Advantages

  • Cost-Efficiency: Emulators and simulators are substantially more cost-effective than buying and maintaining a set of physical devices, as there are uncountable device - OS - browser combinations to be tested. 
  • Availability: These virtual environments are simple to set up and easily accessible, making them an optimal option for testing in the software development life cycle (SDLC). 
  • Parallel Testing: Several emulators or simulators can be launched at once, enabling parallel testing across various operating system versions and device combinations.
  • Repeatable and Consistent: By offering a regulated testing environment, emulators and simulators guarantee consistent testing circumstances and repeatable results. 

b. Disadvantages

  • Limited Realism: Since emulators and simulators are only virtual environments, they can't perfectly simulate the hardware and software characteristics of actual devices. 
  • Hardware-Specific Problems: Some hardware-specific functions like camera, battery life, or GPS should take place in real context to create more precise results. 
  • UI and UX Testing Limitations: Testing UI/UX on virtual environments can be too basic; as capturing the true feeling and responsiveness of real devices, such as touch sensitivity and physical buttons, would be challenging. 

2. Emulator vs Simulator: Key Differences

Although both emulators and simulators share the same function of replicating a mobile device, there are still apparent differences between them.






Replicate both software and hardware aspects

Replicate only the software behavior 


Slower due to hardware emulation

Faster as it does not have to simulate the hardware part

Testing scenarios 

Suitable for more comprehensive testing that includes hardware interactions

Suitable for testing software on its own.

Ease of use 

A bit complex to configure

Easier to set up 

Development stage


Useful in both early and later development stages

Useful in early development stage 

What is a Real Testing Device?

Real testing devices are actual, physical devices supporting a specific testing environment. Testers interact with these devices exactly how an end-user does to look for bugs. It is also possible to execute automated test scripts on these devices, simply by deploying the application and leveraging a test automation framework (Selenium for web or Appium for mobile, for example) to automate interactions. 

Usually, the real testing device is the test environment itself, and teams need to prepare as many devices as the environments they want to test on.

For the purpose of testing, the team usually acquires mobile devices in a great variety of models, including OS, OS versions, screen sizes, etc. Testing on these devices also allows testers to check the functionality and behavioral pattern of the application.


  • Testing on real devices is more reliable because it allows testers to test almost all possible real-time scenarios.
  • Real testing devices can easily simulate battery issues, incoming interrupts, exact color, and brightness displays.
  • It also lets testers carry out usability testing such as the color resolution of the screen, the looks, and feel of the application.


  • Real testing devices are costly
  • Due to the wide variety of handsets to work with, testing on real devices can be challenging, especially when teams are working on a tight timeframe.

Read MoreUltimate Guide to Apply Field Testing for Mobile Application

Emulator & Simulator vs Real Device Testing

When to Use_ Real Testing Device or Virtual Testing Device


Virtual Devices 

(Emulator & Simulator) 

Real Devices 


Results are not as accurate since they can’t mimic every part

More accurate results


Faster deployment and execution

Slower deployment and execution


Cheaper, and in some cases, free to download from the Internet

Costly as it is required to purchase a range of different devices with high maintenance costs 


Relatively easy with built-in tools

Can be tricky

User interaction

Limited by the lack of real touch, feeling and gesture simulation

More realistic representation of user interactions, touch and gesture 

Overall, although virtual devices are made to replicate the software environment of real devices, they are not the same as real devices due to the authenticity of some features. Among some features that virtual devices can’t replicate are push-up notifications, incoming calls, device battery, etc. However, real devices still have some downsides, including debugging and speed, which can be tackled by utilizing the speed and debugging features of simulators and emulators.


When To Use? Real Testing Device vs Virtual Testing Device

Both real devices and virtual devices offer dynamic features, making them more suitable for one phase of testing than the other. Considering mobile testing guidelines, these testing devices can help organizations meet their requirements. The best practices for their use are:

1. The initial phase of testing

Virtual devices can be considered suitable for the beginning of the testing process. They offer a better debugging facility to speed up the testing cycle of the application. In addition, virtual testing devices are cost-effective compared to buying new smartphones. They allow testers to test their application on a wide variety of handsets using different mobile networks around the world.

2. The final phase of testing

For testing the application before release, real testing devices are the best options. It provides more accurate results by allowing testers to check every possible scenario in the testing cycle. Therefore, performance testing, network feasibility, smoke testing, interoperability, sanity testing, and a large part of regression testing should be done on real devices.


Virtual Devices 

(Emulator & Simulator) 

Real Devices 

Functional testing 


Mobile web testing 

UI/UX testing 

Hardware dependence (GPS, CPU) 


Display testing (pixels, resolutions)


Touching gestures (scrolls, zoom in, zoom out) 



Generally, virtual devices would be used first, followed by real devices right before deployment. However, in particular situations, it would be optimal to conduct both of them simultaneously as an effective mobile testing strategy. For instance, to address security concerns and validate proper handling of device permissions, simultaneous testing on both virtual and real devices is crucial, since virtual environments may not completely mimic the security protocols and permission prompts of physical devices.


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Wrapping Up

Mobile testing continues to increase in importance due to the significant role mobile applications play in our everyday lives. Although it requires much testing to reach the stated objectives, one of the ways to achieve that is by choosing the right tools (real devices, simulators, and emulators). However, combining these tools is the best way to create an excellent testing solution, whereby you can save cost, time, and obtain a better ROI.


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Explore Katalon TestCloud, a cloud-based tool that offers flexible, on-demand, and secure multi-browser mobile testing environments. By easily configuring these test environments, you can streamline your testing environment setup, minimizing the time and cost of building any physical infrastructure for automated testing.


To start testing the rich array of environments that Katalon offers, simply download Katalon Studio.



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You can upload your mobile application and later run tests with it. Detailed instructions can be found in Katalon Docs. Writing tests with Katalon is easy when you have access to no-code, low-code, and high-code modes. That means both non-technical and highly experienced testers can write cross-browser test cases the way they want.

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After that, with Katalon TestCloud, you can easily schedule automated test executions on your application. Whether you want to test on iOS or Android, with different phone versions ranging from Samsung Galaxy S22 to Google Pixel 7, TestCloud can still effectively meet your testing requirements. 

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