diff --git a/project/include/ui/Window.h b/project/include/ui/Window.h
index 81e454f10..11b76622f 100644
--- a/project/include/ui/Window.h
+++ b/project/include/ui/Window.h
@@ -39,6 +39,7 @@ namespace lime {
 			virtual int GetHeight () = 0;
 			virtual uint32_t GetID () = 0;
 			virtual bool GetMouseLock () = 0;
+			virtual float GetOpacity () = 0;
 			virtual double GetScale () = 0;
 			virtual bool GetTextInputEnabled () = 0;
 			virtual int GetWidth () = 0;
@@ -55,6 +56,7 @@ namespace lime {
 			virtual bool SetMaximized (bool minimized) = 0;
 			virtual bool SetMinimized (bool minimized) = 0;
 			virtual void SetMouseLock (bool mouseLock) = 0;
+			virtual void SetOpacity (float opacity) = 0;
 			virtual bool SetResizable (bool resizable) = 0;
 			virtual void SetTextInputEnabled (bool enable) = 0;
 			virtual void SetTextInputRect (Rectangle *rect) = 0;
diff --git a/project/src/ExternalInterface.cpp b/project/src/ExternalInterface.cpp
index 08195e7eb..627965521 100644
--- a/project/src/ExternalInterface.cpp
+++ b/project/src/ExternalInterface.cpp
@@ -3350,6 +3350,22 @@ namespace lime {
 	}
 
 
+	double lime_window_get_opacity (value window) {
+
+		Window* targetWindow = (Window*)val_data (window);
+		return (float)targetWindow->GetOpacity ();
+
+	}
+
+
+	HL_PRIM double HL_NAME(hl_window_get_opacity) (HL_CFFIPointer* window) {
+
+		Window* targetWindow = (Window*)window->ptr;
+		return (float)targetWindow->GetOpacity ();
+
+	}
+
+
 	double lime_window_get_scale (value window) {
 
 		Window* targetWindow = (Window*)val_data (window);
@@ -3636,6 +3652,22 @@ namespace lime {
 	}
 
 
+	void lime_window_set_opacity (value window, double opacity) {
+
+		Window* targetWindow = (Window*)val_data (window);
+		targetWindow->SetOpacity ((float)opacity);
+
+	}
+
+
+	HL_PRIM void HL_NAME(hl_window_set_opacity) (HL_CFFIPointer* window, double opacity) {
+
+		Window* targetWindow = (Window*)window->ptr;
+		targetWindow->SetOpacity ((float)opacity);
+
+	}
+
+
 	bool lime_window_set_resizable (value window, bool resizable) {
 
 		Window* targetWindow = (Window*)val_data (window);
@@ -3951,6 +3983,8 @@ namespace lime {
 	DEFINE_PRIME2v (lime_window_set_text_input_rect);
 	DEFINE_PRIME2 (lime_window_set_title);
 	DEFINE_PRIME3v (lime_window_warp_mouse);
+	DEFINE_PRIME1 (lime_window_get_opacity);
+	DEFINE_PRIME2v (lime_window_set_opacity);
 	DEFINE_PRIME2 (lime_zlib_compress);
 	DEFINE_PRIME2 (lime_zlib_decompress);
 
@@ -4135,6 +4169,8 @@ namespace lime {
 	DEFINE_HL_PRIM (_VOID, hl_window_set_text_input_rect, _TCFFIPOINTER _TRECTANGLE);
 	DEFINE_HL_PRIM (_STRING, hl_window_set_title, _TCFFIPOINTER _STRING);
 	DEFINE_HL_PRIM (_VOID, hl_window_warp_mouse, _TCFFIPOINTER _I32 _I32);
+	DEFINE_HL_PRIM (_F64, hl_window_get_opacity, _TCFFIPOINTER);
+	DEFINE_HL_PRIM (_VOID, hl_window_set_opacity, _TCFFIPOINTER _F64);
 	DEFINE_HL_PRIM (_TBYTES, hl_zlib_compress, _TBYTES _TBYTES);
 	DEFINE_HL_PRIM (_TBYTES, hl_zlib_decompress, _TBYTES _TBYTES);
 
diff --git a/project/src/backend/sdl/SDLWindow.cpp b/project/src/backend/sdl/SDLWindow.cpp
index 2c54ec997..6709ca036 100644
--- a/project/src/backend/sdl/SDLWindow.cpp
+++ b/project/src/backend/sdl/SDLWindow.cpp
@@ -496,9 +496,6 @@ namespace lime {
 	}
 
 
-
-
-
 	const char* SDLWindow::GetContextType () {
 
 		if (context) {
@@ -592,6 +589,17 @@ namespace lime {
 	}
 
 
+	float SDLWindow::GetOpacity () {
+
+		float opacity = 1.0f;
+
+		SDL_GetWindowOpacity (sdlWindow, &opacity);
+
+		return opacity;
+
+	}
+
+
 	double SDLWindow::GetScale () {
 
 		if (sdlRenderer) {
@@ -1010,6 +1018,13 @@ namespace lime {
 	}
 
 
+	void SDLWindow::SetOpacity (float opacity) {
+
+		SDL_SetWindowOpacity (sdlWindow, opacity);
+
+	}
+
+
 	bool SDLWindow::SetResizable (bool resizable) {
 
 		#ifndef EMSCRIPTEN
@@ -1076,7 +1091,7 @@ namespace lime {
 	}
 
 
-	void SDLWindow::WarpMouse (int x, int y){
+	void SDLWindow::WarpMouse (int x, int y) {
 
 		SDL_WarpMouseInWindow (sdlWindow, x, y);
 
@@ -1090,4 +1105,4 @@ namespace lime {
 	}
 
 
-}
\ No newline at end of file
+}
diff --git a/project/src/backend/sdl/SDLWindow.h b/project/src/backend/sdl/SDLWindow.h
index c3769ef18..e047076c2 100644
--- a/project/src/backend/sdl/SDLWindow.h
+++ b/project/src/backend/sdl/SDLWindow.h
@@ -33,6 +33,7 @@ namespace lime {
 			virtual int GetHeight ();
 			virtual uint32_t GetID ();
 			virtual bool GetMouseLock ();
+			virtual float GetOpacity ();
 			virtual double GetScale ();
 			virtual bool GetTextInputEnabled ();
 			virtual int GetWidth ();
@@ -49,12 +50,12 @@ namespace lime {
 			virtual bool SetMaximized (bool maximized);
 			virtual bool SetMinimized (bool minimized);
 			virtual void SetMouseLock (bool mouseLock);
+			virtual void SetOpacity (float opacity);
 			virtual bool SetResizable (bool resizable);
 			virtual void SetTextInputEnabled (bool enabled);
 			virtual void SetTextInputRect (Rectangle *rect);
 			virtual const char* SetTitle (const char* title);
 			virtual void WarpMouse (int x, int y);
-
 			SDL_Renderer* sdlRenderer;
 			SDL_Texture* sdlTexture;
 			SDL_Window* sdlWindow;
@@ -71,4 +72,4 @@ namespace lime {
 }
 
 
-#endif
\ No newline at end of file
+#endif
diff --git a/src/lime/_internal/backend/flash/FlashWindow.hx b/src/lime/_internal/backend/flash/FlashWindow.hx
index f61fe3d73..ca155992a 100644
--- a/src/lime/_internal/backend/flash/FlashWindow.hx
+++ b/src/lime/_internal/backend/flash/FlashWindow.hx
@@ -572,6 +572,11 @@ class FlashWindow
 		return false;
 	}
 
+	public function getOpacity():Float
+	{
+		return 1.0;
+	}
+
 	public function getTextInputEnabled():Bool
 	{
 		return textInputEnabled;
@@ -613,6 +618,8 @@ class FlashWindow
 
 	public function setMouseLock(value:Bool):Void {}
 
+	public function setOpacity(value:Float):Void {}
+
 	public function setResizable(value:Bool):Bool
 	{
 		return value;
diff --git a/src/lime/_internal/backend/html5/HTML5Window.hx b/src/lime/_internal/backend/html5/HTML5Window.hx
index a5a636025..592ebad11 100644
--- a/src/lime/_internal/backend/html5/HTML5Window.hx
+++ b/src/lime/_internal/backend/html5/HTML5Window.hx
@@ -393,6 +393,11 @@ class HTML5Window
 		return false;
 	}
 
+	public function getOpacity():Float
+	{
+		return 1.0;
+	}
+
 	public function getTextInputEnabled():Bool
 	{
 		return textInputEnabled;
@@ -1101,6 +1106,8 @@ class HTML5Window
 
 	public function setMouseLock(value:Bool):Void {}
 
+	public function setOpacity(value:Float):Void {}
+
 	public function setResizable(value:Bool):Bool
 	{
 		return value;
diff --git a/src/lime/_internal/backend/native/NativeCFFI.hx b/src/lime/_internal/backend/native/NativeCFFI.hx
index a3da6319b..b31af6e62 100644
--- a/src/lime/_internal/backend/native/NativeCFFI.hx
+++ b/src/lime/_internal/backend/native/NativeCFFI.hx
@@ -305,6 +305,8 @@ class NativeCFFI
 
 	@:cffi private static function lime_window_get_mouse_lock(handle:Dynamic):Bool;
 
+	@:cffi private static function lime_window_get_opacity(handle:Dynamic):Float;
+
 	@:cffi private static function lime_window_get_scale(handle:Dynamic):Float;
 
 	@:cffi private static function lime_window_get_text_input_enabled(handle:Dynamic):Bool;
@@ -337,6 +339,8 @@ class NativeCFFI
 
 	@:cffi private static function lime_window_set_mouse_lock(handle:Dynamic, mouseLock:Bool):Void;
 
+	@:cffi private static function lime_window_set_opacity(handle:Dynamic, value:Float):Void;
+
 	@:cffi private static function lime_window_set_resizable(handle:Dynamic, resizable:Bool):Bool;
 
 	@:cffi private static function lime_window_set_text_input_enabled(handle:Dynamic, enabled:Bool):Void;
@@ -564,6 +568,7 @@ class NativeCFFI
 	private static var lime_window_get_id = new cpp.Callable<cpp.Object->Int>(cpp.Prime._loadPrime("lime", "lime_window_get_id", "oi", false));
 	private static var lime_window_get_mouse_lock = new cpp.Callable<cpp.Object->Bool>(cpp.Prime._loadPrime("lime", "lime_window_get_mouse_lock", "ob",
 		false));
+	private static var lime_window_get_opacity = new cpp.Callable<cpp.Object->Float>(cpp.Prime._loadPrime("lime", "lime_window_get_opacity", "od", false));
 	private static var lime_window_get_scale = new cpp.Callable<cpp.Object->Float>(cpp.Prime._loadPrime("lime", "lime_window_get_scale", "od", false));
 	private static var lime_window_get_text_input_enabled = new cpp.Callable<cpp.Object->Bool>(cpp.Prime._loadPrime("lime",
 		"lime_window_get_text_input_enabled", "ob", false));
@@ -591,6 +596,8 @@ class NativeCFFI
 		false));
 	private static var lime_window_set_mouse_lock = new cpp.Callable<cpp.Object->Bool->cpp.Void>(cpp.Prime._loadPrime("lime", "lime_window_set_mouse_lock",
 		"obv", false));
+	private static var lime_window_set_opacity = new cpp.Callable<cpp.Object->Float->cpp.Void>(cpp.Prime._loadPrime("lime", "lime_window_set_opacity", "odv",
+		false));
 	private static var lime_window_set_resizable = new cpp.Callable<cpp.Object->Bool->Bool>(cpp.Prime._loadPrime("lime", "lime_window_set_resizable", "obb",
 		false));
 	private static var lime_window_set_text_input_enabled = new cpp.Callable<cpp.Object->Bool->cpp.Void>(cpp.Prime._loadPrime("lime",
@@ -733,6 +740,7 @@ class NativeCFFI
 	private static var lime_window_get_height = CFFI.load("lime", "lime_window_get_height", 1);
 	private static var lime_window_get_id = CFFI.load("lime", "lime_window_get_id", 1);
 	private static var lime_window_get_mouse_lock = CFFI.load("lime", "lime_window_get_mouse_lock", 1);
+	private static var lime_window_get_opacity = CFFI.load("lime", "lime_window_get_opacity", 1);
 	private static var lime_window_get_scale = CFFI.load("lime", "lime_window_get_scale", 1);
 	private static var lime_window_get_text_input_enabled = CFFI.load("lime", "lime_window_get_text_input_enabled", 1);
 	private static var lime_window_get_width = CFFI.load("lime", "lime_window_get_width", 1);
@@ -749,6 +757,7 @@ class NativeCFFI
 	private static var lime_window_set_maximized = CFFI.load("lime", "lime_window_set_maximized", 2);
 	private static var lime_window_set_minimized = CFFI.load("lime", "lime_window_set_minimized", 2);
 	private static var lime_window_set_mouse_lock = CFFI.load("lime", "lime_window_set_mouse_lock", 2);
+	private static var lime_window_set_opacity = CFFI.load("lime", "lime_window_set_opacity", 2);
 	private static var lime_window_set_resizable = CFFI.load("lime", "lime_window_set_resizable", 2);
 	private static var lime_window_set_text_input_enabled = CFFI.load("lime", "lime_window_set_text_input_enabled", 2);
 	private static var lime_window_set_text_input_rect = CFFI.load("lime", "lime_window_set_text_input_rect", 2);
@@ -1357,6 +1366,10 @@ class NativeCFFI
 
 	@:hlNative("lime", "hl_window_warp_mouse") private static function lime_window_warp_mouse(handle:CFFIPointer, x:Int, y:Int):Void {}
 
+	@:hlNative("lime", "hl_window_get_opacity") private static function lime_window_get_opacity(handle:CFFIPointer):Float { return 0.0; }
+
+	@:hlNative("lime", "hl_window_set_opacity") private static function lime_window_set_opacity(handle:CFFIPointer, value:Float):Void {}
+
 	@:hlNative("lime", "hl_window_event_manager_register") private static function lime_window_event_manager_register(callback:Void->Void,
 		eventObject:WindowEventInfo):Void {}
 
diff --git a/src/lime/_internal/backend/native/NativeWindow.hx b/src/lime/_internal/backend/native/NativeWindow.hx
index 15a01b05c..08b3079de 100644
--- a/src/lime/_internal/backend/native/NativeWindow.hx
+++ b/src/lime/_internal/backend/native/NativeWindow.hx
@@ -299,6 +299,18 @@ class NativeWindow
 		return mouseLock;
 	}
 
+	public function getOpacity():Float
+	{
+		if (handle != null)
+		{
+			#if (!macro && lime_cffi)
+			return NativeCFFI.lime_window_get_opacity(handle);
+			#end
+		}
+
+		return 1.0;
+	}
+
 	public function getTextInputEnabled():Bool
 	{
 		if (handle != null)
@@ -628,6 +640,16 @@ class NativeWindow
 		return value;
 	}
 
+	public function setOpacity(value:Float):Void
+	{
+		if (handle != null)
+		{
+			#if (!macro && lime_cffi)
+			NativeCFFI.lime_window_set_opacity(handle, value);
+			#end
+		}
+	}
+
 	public function setResizable(value:Bool):Bool
 	{
 		if (handle != null)
diff --git a/src/lime/ui/Window.hx b/src/lime/ui/Window.hx
index 1cdc8dd73..5e82f5787 100644
--- a/src/lime/ui/Window.hx
+++ b/src/lime/ui/Window.hx
@@ -80,6 +80,7 @@ class Window
 	public var onRestore(default, null) = new Event<Void->Void>();
 	public var onTextEdit(default, null) = new Event<String->Int->Int->Void>();
 	public var onTextInput(default, null) = new Event<String->Void>();
+	public var opacity(get, set):Float;
 	public var parameters:Dynamic;
 	public var resizable(get, set):Bool;
 	public var scale(get, null):Float;
@@ -518,6 +519,17 @@ class Window
 		return value;
 	}
 
+	@:noCompletion private function get_opacity():Float
+	{
+		return __backend.getOpacity();
+	}
+
+	@:noCompletion private function set_opacity(value:Float):Float
+	{
+		__backend.setOpacity(value);
+		return value;
+	}
+
 	@:noCompletion private inline function get_resizable():Bool
 	{
 		return __resizable;