Build an iOS application

The process of building an iOS application with Unity has two main steps:

1. Unity generates an Xcode project.
2. Xcode builds the generated project into the application.

For further information on how Unity builds iOS applications, refer to How Unity builds iOS applications.

Note: To build an iOS application locally, your development machine must run macOS as Xcode is available only on macOS devices. If you don’t have a macOS device, you can use Unity Build AutomationA continuous integration service for Unity projects that automates the process of creating builds on Unity’s servers. More info
See in Glossary to build your applications in the cloud.

Before you build your Project for iOS, make sure that you set the Bundle Identifier in the iOS Player SettingsSettings that let you set various player-specific options for the final game built by Unity. More info
See in Glossary (menu: Edit > Project Settings > Player Settings). You can also choose whether your app targets the simulator or an actual device. To do this, change the SDK version field.

Build an Xcode project from the Unity Editor

To build an Xcode project for iOS, use the following steps:

1. Select File > Build Settings.
2. From the list of platforms in the Platform pane, select iOS.
   
   Note: If iOS is unavailable, follow the steps in iOS environment setup.
3. Set any Build Settings your project requires.
4. Choose either Build or Build and Run. If you select Build and Run and use a macOS device, Xcode builds the generated project into the application and then installs the application to a connected iOS device.
5. Choose or create a directory for Unity to build the Xcode project in. If an Xcode project already exists in the target directory, an alert displays with options on how to proceed. For information on the options available, refer to Replace and append mode.

Tip: After you specify the target directory for the first time, you can use Cmd+B to build and run the application. Unity uses the Append mode to regenerate the Xcode project.

For more information on running an Xcode project in Xcode, refer to Building and running an app(Apple Developer).

Replace and append mode

If you build a project in a directory that already contains another Xcode project, Unity displays an alert and a choice on how to proceed. There are two options:

• Replace: Unity removes everything in the target Xcode project directory. It then generates the new Xcode project in the now empty directory.
• Append: Unity removes all files in the target Xcode project root directory and in the Data and Libraries subdirectories. It then fills these directories with newly generated Xcode project content. Unity then updates the Xcode project file according to the latest Unity project changes. Unity only supports this mode for the existing Xcode projects generated with the same Unity iOS version. You can store custom built-in code in the classes subdirectory, as files here aren’t removed.

Run an Xcode project from the command line

After Unity generates the Xcode project, you can build and run the Xcode project from the command line. To do this, use the following steps:

1. Open a Terminal window.
2. Navigate to the Xcode project directory.
3. Find the device ID of the device you want to run the application on. You can find this in Xcode under Window > Devices and Simulators.
4. Enter the following command into the Terminal where <device-id>is your device ID.

unity$ xcodebuild test -destination "platform=iOS,id=<device-id>" -scheme Unity-iPhone

Specify build settings for specific targets

When you use command line arguments to specify build settings, they apply to all targets in your Xcode project. To prevent this, some build settings have suffixed versions which you can use to specify which target your build settings affect. You can implement this through User-Defined settings in Xcode > Build Settings. The APP suffix is used for the application targets and the FRAMEWORKsuffix is used for the framework targets.

When building with xcodebuild, use suffixed versions for the following build settings:

Based on your custom build pipeline, you can extend the list to cover other settings.

Additional resources

• How Unity builds iOS applications
• Structure of a Unity Xcode project
• iOS Build Settings