The System class contains properties related to local settings and operations. Among these are settings for camers and microphones, operations with shared objects and the use of the Clipboard.

Additional properties and methods are in other classes within the openfl.system package: the Capabilities class, the IME class, and the Security class.

This class contains only static methods and properties. You cannot create new instances of the System class.

Static variables

staticread onlytotalMemory:Int

The amount of memory(in bytes) currently in use that has been directly allocated by Flash Player or AIR.

This property does not return all memory used by an OpenFL application or by the application (such as a browser) containing Flash Player content. The browser or operating system may consume other memory. The System.privateMemory property reflects all memory used by an application.

If the amount of memory allocated is greater than the maximum value for a uint object(uint.MAX_VALUE, or 4,294,967,295), then this property is set to 0. The System.totalMemoryNumber property allows larger values.

@:value(false)staticuseCodePage:Bool = false

A Boolean value that determines which code page to use to interpret external text files. When the property is set to false, external text files are interpretted as Unicode. (These files must be encoded as Unicode when you save them.) When the property is set to true, external text files are interpretted using the traditional code page of the operating system running the application. The default value of useCodePage is false.

Text that you load as an external file (using Loader.load(), the URLLoader class or URLStream) must have been saved as Unicode in order for the application to recognize it as Unicode. To encode external files as Unicode, save the files in an application that supports Unicode, such as Notepad on Windows.

If you load external text files that are not Unicode-encoded, set useCodePage to true. Add the following as the first line of code of the file that is loading the data(for Flash Professional, add it to the first frame): System.useCodePage = true;

When this code is present, the application interprets external text using the traditional code page of the operating system. For example, this is generally CP1252 for an English Windows operating system and Shift-JIS for a Japanese operating system.

If you set useCodePage to true, Flash Player 6 and later treat text as Flash Player 5 does.(Flash Player 5 treated all text as if it were in the traditional code page of the operating system running the player.)

If you set useCodePage to true, remember that the traditional code page of the operating system running the application must include the characters used in your external text file in order to display your text. For example, if you load an external text file that contains Chinese characters, those characters cannot display on a system that uses the CP1252 code page because that code page does not include Chinese characters.

To ensure that users on all platforms can view external text files used in your application, you should encode all external text files as Unicode and leave useCodePage set to false. This way, the application(Flash Player 6 and later, or AIR) interprets the text as Unicode.

Static methods


Closes Flash Player.

For the standalone Flash Player debugger version only.

OpenFL applications on desktop operating systems should call the NativeApplication.exit() method to exit the application. It is not recommended to manually exit an application on mobile operating systems.



A value to pass to the operating system. Typically, if the process exits normally, the value is 0.


Forces the garbage collection process.

OpenFL target support: This feature is supported on all desktop operating systems, on iOS, and on Android. This feature is not supported on the html5 target.

For Adobe Flash Player, the System.gc() method is only enabled in the debugger version of the runtime.

In an AIR application, the System.gc() method is only enabled in content running in the AIR Debug Launcher (ADL) or, in an installed application, in content in the application security sandbox.


Pauses Flash Player or the AIR Debug Launcher(ADL). After calling this method, nothing in the application continues except the delivery of Socket events.

For the Flash Player debugger version or the AIR Debug Launcher (ADL) only.


Resumes the application after calling System.pause().

For the Flash Player debugger version or the AIR Debug Launcher (ADL) only.


Replaces the contents of the Clipboard with a specified text string. This method works from any security context when called as a result of a user event(such as a keyboard or input device event handler).

This method is provided for SWF content running in Flash Player 9. It allows only adding String content to the Clipboard.

Flash Player 10 content, content in the application security sandbox in an AIR application, and Haxe "sys" targets can call the Clipboard.setData() method.



A plain-text string of characters to put on the system Clipboard, replacing its current contents(if any).