What Are Simulators and Emulators? An Examination of Emulation vs. Simulation

In 2023, there are more applications in the respective Android and iOS app stroes than ever before. Based on a poll conducted in 2022, there are more than 2.5 million applications and nearly 500,000 publishers in the Google Play Store alone. This speaks to the ever-increasing importance for teams to leverage the use of emulation and simulation testing for their apps.

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 in-depth comparison between emulation vs. simulation, the differences between them, and how to use them as part of your mobile testing strategy.

Emulation vs. Simulation

A simulator creates an environment that mimics the behaviors, variables, and configurations in the production environment of an iOS app. An emulator mimics all the hardware and software features for the Android app production environment of a real device. 

What Are Simulators?

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.

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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?

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.

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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 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. 

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.

Note: This blog was originally published on December 18, 2021, and has since been updated for accuracy and relevance.

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