Table of Contents
Why Use an Emulator
An Android emulator lets you run a virtual Android device on your computer. It behaves like a real phone or tablet that lives inside a window. For a beginner, this is the easiest way to test apps without buying hardware or connecting cables.
You can quickly create different virtual devices, for example a small phone and a large tablet, and run your app on both. This makes it much easier to see how your layouts behave on different screen sizes and Android versions.
Understanding AVD and Android Virtual Devices
The Android emulator uses something called an Android Virtual Device, often called an AVD. An AVD is a configuration that describes a single virtual device. It includes the device model, Android version, screen size, and some hardware options.
You can create many AVDs in Android Studio. Each AVD appears as a separate device in the emulator. When you run your app, you can choose which AVD to use.
An AVD is only a configuration. The emulator is the program that runs that configuration as a virtual device.
Opening the Device Manager
Android Studio includes a tool called Device Manager. You will use it to create and manage AVDs.
You can open Device Manager from the main window of Android Studio. Use the top menu and look for the Tools section, then find Device Manager. In recent versions of Android Studio there is also a Device Manager icon on the right side toolbar.
When Device Manager opens, you see a list of your existing virtual devices. If this is your first time, the list will be empty and Android Studio will invite you to create a new virtual device.
Creating a New Virtual Device
To create an AVD for the first time, use the button to create a new device in Device Manager. This starts a guided process. Android Studio asks you to choose a hardware profile, a system image, and some optional settings.
A hardware profile describes the shape and basic capabilities of the virtual device, such as screen size, resolution, and whether it is a phone, tablet, foldable device, or TV. Android Studio provides many predefined profiles that imitate common real devices.
The next step is to choose a system image. The system image is the actual Android operating system that runs inside the virtual device. You can select a specific Android version and sometimes a variant such as a Google Play version. Picking a recent stable Android version is usually best for learning, for example a version that is not marked as preview.
If the system image you want is not yet downloaded, Android Studio shows a Download link next to it. Downloading a system image can take some time because it is a large file.
After selecting the system image, you move to a final configuration screen. Here you can set the AVD name, the startup orientation, and a few performance related options. Beginners can usually accept the default settings.
Choosing Android Versions for Emulators
An important choice in emulator setup is which Android version to use for each AVD. The version number affects what features are available and how your app behaves.
When you are just starting, it is usually best to create one AVD with a recent stable Android version. This matches what many current devices use. Later, when you start learning about compatibility, you can create additional AVDs with older or newer versions to test behavior across versions.
If you see more than one system image for the same version, such as images with or without Google Play, you can start with a non Google Play image. These images are often a bit lighter and simpler to run. You only need a Google Play image when you want to test features that depend on Google Play Services.
Performance Settings and Hardware Acceleration
The emulator can be demanding on your computer. To keep the virtual device smooth and responsive, Android Studio uses hardware acceleration when possible. This means it uses your computer’s processor and graphics features more directly, which improves performance.
During AVD creation you may see options for graphics performance and managed memory. The default automatic settings usually work well. If your computer struggles, you can create a second AVD with a lower screen resolution or a lower Android version to see if it runs more smoothly.
If the emulator refuses to start or is extremely slow, your system might not support some acceleration options, or they might be disabled. In that case you can adjust emulator settings later through the edit option for an existing AVD in Device Manager.
Starting and Stopping the Emulator
Once you have created an AVD, you can start the emulator from Device Manager. Each AVD in the list has a start button. Clicking it launches the emulator window and boots the virtual device, similar to turning on a real phone.
The first boot can be slow, because the system needs to initialize. Later boots are usually faster. While the emulator is running, your app can use it just like a connected phone.
You can close the emulator by pressing the power button in the emulator window to shut down the virtual device, or by closing the emulator window entirely. If you leave the emulator open, Android Studio can deploy your app to it more quickly, without a full reboot each time.
Basic Emulator Controls
The emulator window includes controls for navigation and some common hardware features. You see a virtual screen with buttons that simulate Home, Back, and the app switcher. These match the common buttons on actual Android devices.
There is also a side panel, often on the right side of the emulator window. This panel provides controls for volume, rotation, power, and other sensors. For example, you can click a rotation control to switch between portrait and landscape. Your layouts should respond to this once you start working with responsive designs.
You can press and hold the virtual power button to see the device power menu, just like on a real phone. You can also use the volume controls to test how your app behaves when volume changes.
Interacting with the Virtual Device
Inside the emulator screen, you interact exactly as you would with a phone. You can click with your mouse to simulate taps, click and drag to simulate swipes, and type using your physical keyboard when a text field is focused.
The emulator includes a virtual home screen, app drawer, and settings app. You can open settings to change language, enable developer options, or look at system information. This can be useful for testing different configurations.
When you install your app from Android Studio, a new icon appears on the emulator’s home screen or in the app drawer. You can tap the icon to open your app, even when Android Studio is not deploying anything.
Installing and Running Your App on the Emulator
After you have at least one AVD available, Android Studio can use it to run your app. When you click the run button in the main toolbar, Android Studio opens a device chooser if more than one target is available. Your emulator AVDs appear there along with any connected physical devices.
If the emulator is not running yet, Android Studio can start it for you. The first deployment of an app to a fresh AVD may take some time, because Android Studio builds the app and then installs it inside the emulator. After the app is installed, pressing run again usually feels much quicker.
As you write more code and update your app, you will use this run process constantly. You can make small code changes and quickly see the effect in the emulator, which is an essential part of the development cycle.
Managing Multiple Virtual Devices
Over time you may create several AVDs. For example, you might have a small phone, a large phone, and a tablet configuration. Device Manager helps you organize these. From there you can rename devices, duplicate them, delete old ones, or edit their configuration.
Running multiple emulators at the same time is possible, but it consumes more memory and processor resources. On a modest computer, it is often better to keep only one or two emulators open at once. You can still switch between different AVDs, just not all at the same moment.
If you often work with one main AVD, you can make it easier to find by giving it a clear name, such as MainPixel or TestPhone. The name does not affect behavior, it only makes the list more understandable.
Common Emulator Issues and Simple Fixes
Beginners often meet a few common problems with the emulator. The virtual device might be slow, refuse to start, or show a black screen. Many of these issues relate to system resources or outdated components.
If the emulator is very slow, close other heavy programs, reduce the emulator window size, or use an AVD with a smaller screen resolution. If possible, keep the emulator open during a whole coding session, rather than constantly closing and reopening it.
If the emulator fails to start or crashes, try updating the Android Emulator component and system images using the Android SDK tools inside Android Studio. You can also recreate the AVD from scratch. Creating a fresh virtual device often resolves strange behavior.
When Android Studio cannot find any devices to run your app, check that at least one AVD exists in Device Manager and that it is running. Then return to the device chooser and select it again.
When to Prefer a Physical Device
Although the emulator is ideal for early learning, there are some cases where a real device is better. The emulator can simulate many features, but some hardware behaviors are more accurate on an actual phone. For example, performance sensitive apps, complex sensors, or some camera based situations are harder to test in an emulator.
For this course, most examples will work perfectly in an emulator, so you can finish almost all exercises without a physical device. Later, when you want to experience how your app feels in daily use, using a real device becomes more useful.
Keeping Your Emulator Setup Healthy
Emulator files and system images take space on your disk. From time to time, visit Device Manager and remove AVDs you no longer use. You can also remove older system images that are no longer needed through the Android SDK tools area.
Make a habit of updating the emulator and tools occasionally. New versions often improve speed and fix bugs. However, you do not need to update before every session. For a beginner, updating once in a while is enough, especially when Android Studio suggests a stable update.
With a clean and updated set of AVDs, the emulator will be a steady and reliable part of your workflow as you continue through the course and start building more complex Android applications.