Version: Unity 6 Preview (6000.0)
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Conditional compilation in Unity
Custom scripting symbols

Unity scripting symbol reference

Platform symbols

Unity automatically defines certain symbols based on the authoring and build target platform. These are as follows:

Define Function
UNITY_EDITOR Scripting symbol to call Unity Editor scriptsA piece of code that allows you to create your own Components, trigger game events, modify Component properties over time and respond to user input in any way you like. More info
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from your game code.
UNITY_EDITOR_WIN Scripting symbol for Editor code on Windows.
UNITY_EDITOR_OSX Scripting symbol for Editor code in macOS.
UNITY_EDITOR_LINUX Scripting symbol for Editor code on Linux.
UNITY_EMBEDDED_LINUX Scripting symbol for embedded Linux.
UNITY_QNX Scripting symbol for QNX.
UNITY_STANDALONE_OSX Scripting symbol to compile or execute code specifically for macOS (including Universal, PPC and Intel architectures).
UNITY_STANDALONE_WIN Scripting symbol for compiling/executing code specifically for Windows standalone applications.
UNITY_STANDALONE_LINUX Scripting symbol for compiling/executing code specifically for Linux standalone applications.
UNITY_SERVER Scripting symbol for compiling/executing code for a dedicated server (macOS, Windows or Linux).
UNITY_IOS Scripting symbol for compiling/executing code for the iOS platform.
UNITY_ANDROID Scripting symbol for the Android platform.
UNITY_TVOS Scripting symbol for the Apple TV platform.
UNITY_VISIONOS Scripting symbol for the VisionOS platform.
UNITY_WSA Scripting symbol for Universal Windows PlatformAn IAP feature that supports Microsoft’s In App Purchase simulator, which allows you to test IAP purchase flows on devices before publishing your application. More info
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.
UNITY_WSA_10_0 Scripting symbol for Universal Windows Platform.
UNITY_WEBGL Scripting symbol for Web.
UNITY_ANALYTICS Scripting symbol for calling Unity AnalyticsAbbreviation of Unity Analytics
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methods from your game code.
UNITY_ASSERTIONS Scripting symbol for assertions control process.
UNITY_64 Scripting symbol for 64-bit platforms. In practice this should not be used because it does not work on all 64-bit architectures and different CPU architectures on a given platform can share the same compiled assemblies. To execute code conditionally based on architecture, use a standard if statement that checks IntPtr.Size, which is 4 in a 32-bit process and 8 in a 64-bit process. For an example, refer to Alternatives to directives.

Unity Editor version symbols

Unity automatically defines certain scripting symbols based on the version of the Unity Editor that you’re currently using.

Given a version number X.Y.Z (for example, 2019.4.14), Unity exposes three global scripting symbols in the following formats: UNITY_X, UNITY_X_Y and UNITY_X_Y_Z.

Here is an example of scripting symbols exposed in Unity 2019.4.14:

Define Function
UNITY_2019 Scripting symbol for the release version of Unity 2019, exposed in every 2019.Y.Z release.
UNITY_2019_4 Scripting symbol for the major version of Unity 2019.4, exposed in every 2019.4.Z release.
UNITY_2019_4_14 Scripting symbol for the minor version of Unity 2019.4.14.

You can also compile code selectively based on the earliest version of Unity required to compile or execute a section of code snippet. Following the same version format as above (X.Y), Unity exposes one global #define in the format UNITY_X_Y_OR_NEWER, that you can use for this purpose.

Other symbols

The other symbols Unity defines are:

Define Function
CSHARP_7_3_OR_NEWER Defined when building scripts with support for C# 7.3 or newer.
ENABLE_MONO Scripting back end #define for Mono.
ENABLE_IL2CPP Scripting back end #define for IL2CPPA Unity-developed scripting back-end which you can use as an alternative to Mono when building projects for some platforms. More info
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.
ENABLE_VR Defined when the target build platform supports VRVirtual Reality More info
See in Glossary
. Doesn’t imply that VR is currently enabled or that the necessary plug-insA set of code created outside of Unity that creates functionality in Unity. There are two kinds of plug-ins you can use in Unity: Managed plug-ins (managed .NET assemblies created with tools like Visual Studio) and Native plug-ins (platform-specific native code libraries). More info
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and packages needed to support VR are installed.
NET_2_0 Defined when building scripts against .NET 2.0 API compatibility level on Mono and IL2CPP.
NET_2_0_SUBSET Defined when building scripts against .NET 2.0 Subset API compatibility level on Mono and IL2CPP.
NET_LEGACY Defined when building scripts against .NET 2.0 or .NET 2.0 Subset API compatibility level on Mono and IL2CPP.
NET_4_6 Defined when building scripts against .NET 4.x API compatibility level on Mono and IL2CPP.
NET_STANDARD_2_0 Defined when building scripts against .NET Standard 2.0 API compatibility level on Mono and IL2CPP.
NET_STANDARD_2_1 Defined when building scripts against .NET Standard 2.1 API compatibility level on Mono and IL2CPP.
NET_STANDARD Defined when building scripts against .NET Standard 2.1 API compatibility level on Mono and IL2CPP.
NETSTANDARD2_1 Defined when building scripts against .NET Standard 2.1 API compatibility level on Mono and IL2CPP.
NETSTANDARD Defined when building scripts against .NET Standard 2.1 API compatibility level on Mono and IL2CPP.
ENABLE_WINMD_SUPPORT Defined when Windows Runtime support is enabled on IL2CPP. For more information, refer to Windows Runtime Support.
ENABLE_INPUT_SYSTEM Defined when the Input System package is enabled in Player SettingsSettings that let you set various player-specific options for the final game built by Unity. More info
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.
ENABLE_LEGACY_INPUT_MANAGER Defined when the legacy Input ManagerSettings where you can define all the different input axes, buttons and controls for your project. More info
See in Glossary
is enabled in Player Settings.
DEVELOPMENT_BUILD Defined when your script is running in a Player which was built with the Development Build option enabled.

This define only reflects whether the development build option was enabled at the time of the build. To know whether your script is running in the development build mode, use Debug.isDebugBuild. __DEVELOPMENT\_BUILD__ isn’t sufficient to determine whether you’re currently running in a development build because most platforms allow changing between development and non-development build without rebuilding the project. However, on some platforms, Unity doesn’t support switching between development and non-development builds in the Editor and requires you to switch after the build is complete. For example, on Windows, you can choose the Create Visual Studio solution option to choose whether you want a development or non-development build in Visual Studio. Switching in Visual Studio doesn’t recompile your scripts and therefore, it will not reevaluate scripting defines. You can also switch from the final game build to a development build by swapping UnityPlayer.dll in the game build with the one from a development build for debugging live game builds.
UNITY_CLOUD_BUILD Defined when the project is built with 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
.

Note: The DEBUG symbol is predefined in C# and in Unity using the directive #if DEBUG is equivalent to #if UNITY_EDITOR || DEVELOPMENT_BUILD

Additional resources

Conditional compilation in Unity
Custom scripting symbols