Blog
March 14, 2023
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.
Back to topWhat Are Simulators vs. Emulators?
What are emulators and simulators? 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.
| Feature | Simulators | Emulators |
|---|---|---|
| Definition | Mimics behaviors, variables, and configurations in the production environment of an iOS app. | Mimics all hardware and software features for the Android app production environment. |
| Purpose | Simulates the basic behavior of a real device. | Emulates the complete hardware and software of a real device. |
| Environment | Virtual environment replicating real-world behavior. | Virtual environment imitating the real device's hardware and software. |
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.
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.
Back to topWhat 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.
Back to topWhat Is the Difference Between an Emulator and Simulator?
| Criteria | Simulation | Emulation |
|---|---|---|
| Provided by | Device manufacturers and other companies. | Device manufacturers. |
| Target area | Internal behavior of the mobile device. | Mobile device hardware, software, and operating system. |
| Internal structure | Written in high-level language. | Written in machine-level assembly language. |
| Used/suitable for | Unit testing, automation testing. | Unit testing, automation testing, debugging. |
| Performance | Faster compared to emulators. | Slower due to latency since it involves binary translation. |
| Reliability | Low, 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.
Back to topEmulation 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.
| Phase of Build Cycle | Recommended Testing Platform | Purpose |
|---|---|---|
| Early Sprint Phases | Emulators and Simulators | Run smoke tests, unit tests, and fast validations in the developer environment. |
| Later Build Process | Real Devices | Ensure test coverage, quality insights, and real user condition testing. |
| Regression/Performance Testing | Real Devices | Test against real environment conditions to avoid defects escaping. |
Back to top
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 (now defunct). 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.”
Back to topEmulation, 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.
See how Perfecto works across mobile, web, and desktop testing, scriptless automation, AI-driven execution, and analytics in these guided demos.
Frequently Asked Questions (FAQ)
1. What is the difference between emulators and simulators?
Emulators mimic both the hardware and software of a real device, while simulators replicate the behavior and environment of a device without imitating its hardware.
2. When should I use emulators or simulators in mobile testing?
Use emulators and simulators during the early sprint phases for smoke tests, unit tests, and fast validations. They are ideal for quick feedback in the development environment.
3. Are emulators or simulators faster for testing?
Simulators are generally faster than emulators because they do not involve binary translation, which can cause latency in emulators.
4. Can emulators and simulators replace real device testing?
No, while they are useful for early testing phases, real device testing is essential for regression, performance, and end-to-end testing to ensure accurate results and avoid defects.
5. How does Perfecto AI enhance mobile testing?
Perfecto AI streamlines mobile testing by providing a unified platform to test on thousands of real and virtual devices, ensuring comprehensive coverage and faster feedback.
6. What are the benefits of using Perfecto AI for emulation and simulation?
Perfecto AI allows teams to seamlessly integrate emulators, simulators, and real devices into their testing strategy, optimizing resources and improving testing efficiency.