December 18, 2021

Emulation vs. Simulation

Continuous Testing

Often the terms simulation and emulation are used interchangeably. But, there is a distinct difference between emulators vs. simulators. Both mimic the real thing in a virtual environment. However, the differences between emulation vs. simulation are quite big when it comes to mobile automation. 

Keep reading for an emulation definition, simulation definition, and to understand the differences between them.

Emulation vs. Simulation

For iOS apps, a simulator creates an environment that mimics the behaviors, variables, and configurations that exist in an app’s production environment. For Android apps, an emulator is designed to mimic all of the hardware and software features for the production environment of a real device.

What Is a Simulator?

Simulators mimic the basic behaviors of a real device. Simulators mean you're copying things from the real world into a virtual environment to give an idea about how that thing would work. It simulates the basic behavior but doesn’t necessarily follow all the rules of the real environment.

Virtual platforms ebook


Related Reading:

How to Achieve High-Velocity Testing By Combining Virtual and Real Devices



A simulator in mobile testing is also a virtual device. It allows you to test your app by simulating the behavior of a real device.

What Are Emulators?

Emulators mimic all of the hardware and software features for the production environment of a real device.

Emulation means basically a complete imitation of the real thing. It just operates in a virtual environment instead of the real world.

An emulator in mobile testing is a virtual device. It allows you to test your app by emulating a real device. A device emulator mimics the hardware or OS of the device.

What Is the Difference Between an Emulator and Simulator?

Differences Between Emulation vs. Simulation
Provided byDevice manufacturers and other companies.Device manufacturers.
Target areaInternal behavior of the mobile device.Mobile device hardware, software, and operating system.
Internal structureWritten in high-level language.Written in machine-level assembly language.
Used/suitable forUnit testing, automation testing.Unit testing, automation testing, debugging.
PerformanceFaster compared to emulators.Slower due to latency since it involves binary translation.
ReliabilityLow, as it cannot simulate all types of user interactions.Same for emulation, as it cannot simulate all types of user interactions.


Emulation and simulation serve a very important goal during the SDLC. They greatly reduce costs to the developers and testers. Some would argue that they are faster to set up and execute, have lower error rates, and are already embedded in the developer’s environment in most cases. This is very convenient from a fast feedback perspective.

Emulation vs. Simulation: When Should You Use Them?

The best practice for mobile app testing should rely on a mix of tests. These tests should be spread across emulators, simulators, and real devices, based on the build phase.

In the early sprint phases, when the features are only shaping up, it makes a lot of sense to run smoke tests, unit tests, other types of testing and fast validations against emulators from the developer environment.

Later in the build process, when the test coverage requirements and the quality insights are greater, launching the full testing scope in parallel against real devices is the right way to go. You can also add real user conditions for a truer testing experience.

Real or Virtual? When, Where, & How to Use Emulators & Simulators

Watch the webinar below to learn more about when you should use real vs. virtual devices.

Get the Right Mix of Virtual and Real Platforms

Virtual platforms are important and beneficial early in the build cycle. However, as you progress to regression, performance, and end-to-end testing, you must test against real environment conditions, or else you risk defects escaping.

Brands testing only with emulation or simulation put their apps at risk of defects. Take for instance the following examples of real user reviews from App Annie. Both SiriusXM and Best Buy encountered issues in their apps due to a lack of real device testing. And as you can see below, it impacted the end-user experience.

App Reviews From Real Users

SiriusXM app review via App Annie: “I’ve used this app for more than a year, but it needs work. Often times even when connected to a solid Wi-Fi connection it will hang on bringing up the home screen. Also when casting to a Chromecast it often crashes.”

Best Buy app review via App Annie: “It is not working on my Samsung S10.”

Best Buy app review via Ann Annie: “BAD UPDATE!!! Now the app does not open on my Xiaomi Mi A1.”

Emulation, Simulation, & Real Device Testing With Perfecto

Testing with emulators, simulators, and real devices is essential for a comprehensive mobile test strategy that makes the most of your team's resources. With Perfecto, teams can test on thousands of real and virtual devices all within the same platform. 

With this ideal testing strategy in the Perfecto cloud, you will also have access to:

  • Real Macs and Windows VMs for web app testing.
  • Unshakeable enterprise-grade security.
  • Extended test coverage.
  • Elastic scaling of your tests.
  • 24/7 access to the cloud.
  • Robust test analytics.

Get ready to achieve high-velocity, cost-effective mobile testing. Try testing on simulators, emulators, and real devices with Perfecto today with our free trial, or sign up for a custom demo of Perfecto with one of our experts.

Start Trial

Get My Demo

Related Content