diff --git a/v3/STATUS.md b/v3/STATUS.md
index 0a0a9d687..5ed7c2dba 100644
--- a/v3/STATUS.md
+++ b/v3/STATUS.md
@@ -31,15 +31,14 @@ Webview Window Interface Methods
 | center()                                           | Y       |       | Y   |                                          |
 | close()                                            |         |       | Y   |                                          |
 | destroy()                                          |         |       | Y   |                                          |
-| disableSizeConstraints()                           |         |       | Y   |                                          |
 | execJS(js string)                                  |         |       | Y   |                                          |
 | forceReload()                                      |         |       | Y   |                                          |
-| fullscreen()                                       |         |       | Y   |                                          |
+| fullscreen()                                       | Y       |       | Y   |                                          |
 | getScreen() (*Screen, error)                       |         |       | Y   |                                          |
 | getZoom() float64                                  |         |       | Y   |                                          |
 | height() int                                       | Y       |       | Y   |                                          |
 | hide()                                             | Y       |       | Y   |                                          |
-| isFullscreen() bool                                |         |       | Y   |                                          |
+| isFullscreen() bool                                | Y       |       | Y   |                                          |
 | isMaximised() bool                                 | Y       |       | Y   |                                          |
 | isMinimised() bool                                 | Y       |       | Y   |                                          |
 | maximise()                                         | Y       |       | Y   |                                          |
@@ -64,9 +63,9 @@ Webview Window Interface Methods
 | setURL(url string)                                 |         |       | Y   |                                          |
 | setZoom(zoom float64)                              |         |       | Y   |                                          |
 | show()                                             | Y       |       | Y   |                                          |
-| size() (int, int)                                  |         |       | Y   |                                          |
+| size() (int, int)                                  | Y       |       | Y   |                                          |
 | toggleDevTools()                                   |         |       | Y   |                                          |
-| unfullscreen()                                     |         |       | Y   |                                          |
+| unfullscreen()                                     | Y       |       | Y   |                                          |
 | unmaximise()                                       | Y       |       | Y   |                                          |
 | unminimise()                                       | Y       |       | Y   |                                          |
 | width() int                                        | Y       |       | Y   |                                          |
diff --git a/v3/pkg/application/application.go b/v3/pkg/application/application.go
index 08f52aaf5..8fb8152ed 100644
--- a/v3/pkg/application/application.go
+++ b/v3/pkg/application/application.go
@@ -614,3 +614,35 @@ func (a *App) GetWindowByName(name string) *WebviewWindow {
 	}
 	return nil
 }
+
+func invokeSync(fn func()) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+	globalApplication.dispatchOnMainThread(func() {
+		fn()
+		wg.Done()
+	})
+	wg.Wait()
+}
+
+func invokeSyncWithResult[T any](fn func() T) (res T) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+	globalApplication.dispatchOnMainThread(func() {
+		res = fn()
+		wg.Done()
+	})
+	wg.Wait()
+	return res
+}
+
+func invokeSyncWithResultAndError[T any](fn func() (T, error)) (res T, err error) {
+	var wg sync.WaitGroup
+	wg.Add(1)
+	globalApplication.dispatchOnMainThread(func() {
+		res, err = fn()
+		wg.Done()
+	})
+	wg.Wait()
+	return res, err
+}
diff --git a/v3/pkg/application/webview_window.go b/v3/pkg/application/webview_window.go
index cd7f874e4..1537cd8b3 100644
--- a/v3/pkg/application/webview_window.go
+++ b/v3/pkg/application/webview_window.go
@@ -136,7 +136,9 @@ func (w *WebviewWindow) SetTitle(title string) *WebviewWindow {
 	defer w.implLock.RUnlock()
 	w.options.Title = title
 	if w.impl != nil {
-		w.impl.setTitle(title)
+		invokeSync(func() {
+			w.impl.setTitle(title)
+		})
 	}
 	return w
 }
@@ -182,7 +184,9 @@ func (w *WebviewWindow) SetSize(width, height int) *WebviewWindow {
 	}
 
 	if w.impl != nil {
-		w.impl.setSize(width, height)
+		invokeSync(func() {
+			w.impl.setSize(width, height)
+		})
 	}
 	return w
 }
@@ -194,14 +198,16 @@ func (w *WebviewWindow) run() {
 	w.implLock.Lock()
 	w.impl = newWindowImpl(w)
 	w.implLock.Unlock()
-	w.impl.run()
+	invokeSync(w.impl.run)
 }
 
 // SetAlwaysOnTop sets the window to be always on top.
 func (w *WebviewWindow) SetAlwaysOnTop(b bool) *WebviewWindow {
 	w.options.AlwaysOnTop = b
 	if w.impl != nil {
-		w.impl.setAlwaysOnTop(b)
+		invokeSync(func() {
+			w.impl.setAlwaysOnTop(b)
+		})
 	}
 	return w
 }
@@ -215,7 +221,7 @@ func (w *WebviewWindow) Show() *WebviewWindow {
 		w.run()
 		return w
 	}
-	w.impl.show()
+	invokeSync(w.impl.show)
 	return w
 }
 
@@ -223,7 +229,7 @@ func (w *WebviewWindow) Show() *WebviewWindow {
 func (w *WebviewWindow) Hide() *WebviewWindow {
 	w.options.Hidden = true
 	if w.impl != nil {
-		w.impl.hide()
+		invokeSync(w.impl.hide)
 	}
 	return w
 }
@@ -231,7 +237,9 @@ func (w *WebviewWindow) Hide() *WebviewWindow {
 func (w *WebviewWindow) SetURL(s string) *WebviewWindow {
 	w.options.URL = s
 	if w.impl != nil {
-		w.impl.setURL(s)
+		invokeSync(func() {
+			w.impl.setURL(s)
+		})
 	}
 	return w
 }
@@ -240,7 +248,9 @@ func (w *WebviewWindow) SetURL(s string) *WebviewWindow {
 func (w *WebviewWindow) SetZoom(magnification float64) *WebviewWindow {
 	w.options.Zoom = magnification
 	if w.impl != nil {
-		w.impl.setZoom(magnification)
+		invokeSync(func() {
+			w.impl.setZoom(magnification)
+		})
 	}
 	return w
 }
@@ -248,7 +258,7 @@ func (w *WebviewWindow) SetZoom(magnification float64) *WebviewWindow {
 // GetZoom returns the current zoom level of the window.
 func (w *WebviewWindow) GetZoom() float64 {
 	if w.impl != nil {
-		return w.impl.getZoom()
+		return invokeSyncWithResult(w.impl.getZoom)
 	}
 	return 1
 }
@@ -257,7 +267,9 @@ func (w *WebviewWindow) GetZoom() float64 {
 func (w *WebviewWindow) SetResizable(b bool) *WebviewWindow {
 	w.options.DisableResize = !b
 	if w.impl != nil {
-		w.impl.setResizable(b)
+		invokeSync(func() {
+			w.impl.setResizable(b)
+		})
 	}
 	return w
 }
@@ -288,9 +300,13 @@ func (w *WebviewWindow) SetMinSize(minWidth, minHeight int) *WebviewWindow {
 	}
 	if w.impl != nil {
 		if newSize {
-			w.impl.setSize(newWidth, newHeight)
+			invokeSync(func() {
+				w.impl.setSize(newWidth, newHeight)
+			})
 		}
-		w.impl.setMinSize(minWidth, minHeight)
+		invokeSync(func() {
+			w.impl.setMinSize(minWidth, minHeight)
+		})
 	}
 	return w
 }
@@ -316,9 +332,13 @@ func (w *WebviewWindow) SetMaxSize(maxWidth, maxHeight int) *WebviewWindow {
 	}
 	if w.impl != nil {
 		if newSize {
-			w.impl.setSize(newWidth, newHeight)
+			invokeSync(func() {
+				w.impl.setSize(newWidth, newHeight)
+			})
 		}
-		w.impl.setMaxSize(maxWidth, maxHeight)
+		invokeSync(func() {
+			w.impl.setMaxSize(maxWidth, maxHeight)
+		})
 	}
 	return w
 }
@@ -339,7 +359,7 @@ func (w *WebviewWindow) Fullscreen() *WebviewWindow {
 	}
 	if !w.IsFullscreen() {
 		w.disableSizeConstraints()
-		w.impl.fullscreen()
+		invokeSync(w.impl.fullscreen)
 	}
 	return w
 }
@@ -347,7 +367,9 @@ func (w *WebviewWindow) Fullscreen() *WebviewWindow {
 func (w *WebviewWindow) SetFullscreenButtonEnabled(enabled bool) *WebviewWindow {
 	w.options.FullscreenButtonEnabled = enabled
 	if w.impl != nil {
-		w.impl.setFullscreenButtonEnabled(enabled)
+		invokeSync(func() {
+			w.impl.setFullscreenButtonEnabled(enabled)
+		})
 	}
 	return w
 }
@@ -357,7 +379,7 @@ func (w *WebviewWindow) IsMinimised() bool {
 	if w.impl == nil {
 		return false
 	}
-	return w.impl.isMinimised()
+	return invokeSyncWithResult(w.impl.isMinimised)
 }
 
 // IsVisible returns true if the window is visible
@@ -365,7 +387,7 @@ func (w *WebviewWindow) IsVisible() bool {
 	if w.impl == nil {
 		return false
 	}
-	return w.impl.isVisible()
+	return invokeSyncWithResult(w.impl.isVisible)
 }
 
 // IsMaximised returns true if the window is maximised
@@ -373,15 +395,19 @@ func (w *WebviewWindow) IsMaximised() bool {
 	if w.impl == nil {
 		return false
 	}
-	return w.impl.isMaximised()
+	return invokeSyncWithResult(w.impl.isMaximised)
 }
 
 // Size returns the size of the window
-func (w *WebviewWindow) Size() (width int, height int) {
+func (w *WebviewWindow) Size() (int, int) {
 	if w.impl == nil {
 		return 0, 0
 	}
-	return w.impl.size()
+	var width, height int
+	invokeSync(func() {
+		width, height = w.impl.size()
+	})
+	return width, height
 }
 
 // IsFullscreen returns true if the window is fullscreen
@@ -391,14 +417,16 @@ func (w *WebviewWindow) IsFullscreen() bool {
 	if w.impl == nil {
 		return false
 	}
-	return w.impl.isFullscreen()
+	return invokeSyncWithResult(w.impl.isFullscreen)
 }
 
 // SetBackgroundColour sets the background colour of the window
 func (w *WebviewWindow) SetBackgroundColour(colour RGBA) *WebviewWindow {
 	w.options.BackgroundColour = colour
 	if w.impl != nil {
-		w.impl.setBackgroundColour(colour)
+		invokeSync(func() {
+			w.impl.setBackgroundColour(colour)
+		})
 	}
 	return w
 }
@@ -407,7 +435,9 @@ func (w *WebviewWindow) handleMessage(message string) {
 	w.info(message)
 	// Check for special messages
 	if message == "test" {
-		w.SetTitle("Hello World")
+		invokeSync(func() {
+			w.SetTitle("Hello World")
+		})
 	}
 	w.info("ProcessMessage from front end:", message)
 
@@ -418,7 +448,7 @@ func (w *WebviewWindow) Center() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.center()
+	invokeSync(w.impl.center)
 }
 
 // On registers a callback for the given window event
@@ -455,7 +485,7 @@ func (w *WebviewWindow) Width() int {
 	if w.impl == nil {
 		return 0
 	}
-	return w.impl.width()
+	return invokeSyncWithResult(w.impl.width)
 }
 
 // Height returns the height of the window
@@ -463,7 +493,7 @@ func (w *WebviewWindow) Height() int {
 	if w.impl == nil {
 		return 0
 	}
-	return w.impl.height()
+	return invokeSyncWithResult(w.impl.height)
 }
 
 // Position returns the position of the window
@@ -473,7 +503,11 @@ func (w *WebviewWindow) Position() (int, int) {
 	if w.impl == nil {
 		return 0, 0
 	}
-	return w.impl.position()
+	var x, y int
+	invokeSync(func() {
+		x, y = w.impl.position()
+	})
+	return x, y
 }
 
 func (w *WebviewWindow) Destroy() {
@@ -484,7 +518,7 @@ func (w *WebviewWindow) Destroy() {
 	for _, cancelFunc := range w.cancellers {
 		cancelFunc()
 	}
-	w.impl.destroy()
+	invokeSync(w.impl.destroy)
 }
 
 // Reload reloads the page assets
@@ -492,7 +526,7 @@ func (w *WebviewWindow) Reload() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.reload()
+	invokeSync(w.impl.reload)
 }
 
 // ForceReload forces the window to reload the page assets
@@ -500,7 +534,7 @@ func (w *WebviewWindow) ForceReload() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.forceReload()
+	invokeSync(w.impl.forceReload)
 }
 
 // ToggleFullscreen toggles the window between fullscreen and normal
@@ -508,24 +542,26 @@ func (w *WebviewWindow) ToggleFullscreen() {
 	if w.impl == nil {
 		return
 	}
-	if w.IsFullscreen() {
-		w.UnFullscreen()
-	} else {
-		w.Fullscreen()
-	}
+	invokeSync(func() {
+		if w.IsFullscreen() {
+			w.UnFullscreen()
+		} else {
+			w.Fullscreen()
+		}
+	})
 }
 
 func (w *WebviewWindow) ToggleDevTools() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.toggleDevTools()
+	invokeSync(w.impl.toggleDevTools)
 }
 
 // ZoomReset resets the zoom level of the webview content to 100%
 func (w *WebviewWindow) ZoomReset() *WebviewWindow {
 	if w.impl != nil {
-		w.impl.zoomReset()
+		invokeSync(w.impl.zoomReset)
 	}
 	return w
 
@@ -536,7 +572,7 @@ func (w *WebviewWindow) ZoomIn() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.zoomIn()
+	invokeSync(w.impl.zoomIn)
 }
 
 // ZoomOut decreases the zoom level of the webview content
@@ -544,7 +580,7 @@ func (w *WebviewWindow) ZoomOut() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.zoomOut()
+	invokeSync(w.impl.zoomOut)
 }
 
 // Close closes the window
@@ -552,21 +588,23 @@ func (w *WebviewWindow) Close() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.close()
+	invokeSync(w.impl.close)
 }
 
 func (w *WebviewWindow) Zoom() {
 	if w.impl == nil {
 		return
 	}
-	w.impl.zoom()
+	invokeSync(w.impl.zoom)
 }
 
 // SetHTML sets the HTML of the window to the given html string.
 func (w *WebviewWindow) SetHTML(html string) *WebviewWindow {
 	w.options.HTML = html
 	if w.impl != nil {
-		w.impl.setHTML(html)
+		invokeSync(func() {
+			w.impl.setHTML(html)
+		})
 	}
 	return w
 }
@@ -576,7 +614,9 @@ func (w *WebviewWindow) SetPosition(x, y int) *WebviewWindow {
 	w.options.X = x
 	w.options.Y = y
 	if w.impl != nil {
-		w.impl.setPosition(x, y)
+		invokeSync(func() {
+			w.impl.setPosition(x, y)
+		})
 	}
 	return w
 }
@@ -588,7 +628,7 @@ func (w *WebviewWindow) Minimise() *WebviewWindow {
 		return w
 	}
 	if !w.IsMinimised() {
-		w.impl.minimise()
+		invokeSync(w.impl.minimise)
 	}
 	return w
 }
@@ -601,7 +641,7 @@ func (w *WebviewWindow) Maximise() *WebviewWindow {
 	}
 	if !w.IsMaximised() {
 		w.disableSizeConstraints()
-		w.impl.maximise()
+		invokeSync(w.impl.maximise)
 	}
 	return w
 }
@@ -612,7 +652,7 @@ func (w *WebviewWindow) UnMinimise() {
 		return
 	}
 	if w.IsMinimised() {
-		w.impl.unminimise()
+		invokeSync(w.impl.unminimise)
 	}
 }
 
@@ -623,7 +663,7 @@ func (w *WebviewWindow) UnMaximise() {
 	}
 	if w.IsMaximised() {
 		w.enableSizeConstraints()
-		w.impl.unmaximise()
+		invokeSync(w.impl.unmaximise)
 	}
 }
 
@@ -634,7 +674,7 @@ func (w *WebviewWindow) UnFullscreen() {
 	}
 	if w.IsFullscreen() {
 		w.enableSizeConstraints()
-		w.impl.unfullscreen()
+		invokeSync(w.impl.unfullscreen)
 	}
 }
 
@@ -643,37 +683,43 @@ func (w *WebviewWindow) Restore() {
 	if w.impl == nil {
 		return
 	}
-	if w.IsMinimised() {
-		w.UnMinimise()
-	} else if w.IsMaximised() {
-		w.UnMaximise()
-	} else if w.IsFullscreen() {
-		w.UnFullscreen()
-	}
+	invokeSync(func() {
+		if w.IsMinimised() {
+			w.UnMinimise()
+		} else if w.IsMaximised() {
+			w.UnMaximise()
+		} else if w.IsFullscreen() {
+			w.UnFullscreen()
+		}
+	})
 }
 
 func (w *WebviewWindow) disableSizeConstraints() {
 	if w.impl == nil {
 		return
 	}
-	if w.options.MinWidth > 0 && w.options.MinHeight > 0 {
-		w.impl.setMinSize(0, 0)
-	}
-	if w.options.MaxWidth > 0 && w.options.MaxHeight > 0 {
-		w.impl.setMaxSize(0, 0)
-	}
+	invokeSync(func() {
+		if w.options.MinWidth > 0 && w.options.MinHeight > 0 {
+			w.impl.setMinSize(0, 0)
+		}
+		if w.options.MaxWidth > 0 && w.options.MaxHeight > 0 {
+			w.impl.setMaxSize(0, 0)
+		}
+	})
 }
 
 func (w *WebviewWindow) enableSizeConstraints() {
 	if w.impl == nil {
 		return
 	}
-	if w.options.MinWidth > 0 && w.options.MinHeight > 0 {
-		w.SetMinSize(w.options.MinWidth, w.options.MinHeight)
-	}
-	if w.options.MaxWidth > 0 && w.options.MaxHeight > 0 {
-		w.SetMaxSize(w.options.MaxWidth, w.options.MaxHeight)
-	}
+	invokeSync(func() {
+		if w.options.MinWidth > 0 && w.options.MinHeight > 0 {
+			w.SetMinSize(w.options.MinWidth, w.options.MinHeight)
+		}
+		if w.options.MaxWidth > 0 && w.options.MaxHeight > 0 {
+			w.SetMaxSize(w.options.MaxWidth, w.options.MaxHeight)
+		}
+	})
 }
 
 // GetScreen returns the screen that the window is on
@@ -681,14 +727,16 @@ func (w *WebviewWindow) GetScreen() (*Screen, error) {
 	if w.impl == nil {
 		return nil, nil
 	}
-	return w.impl.getScreen()
+	return invokeSyncWithResultAndError(w.impl.getScreen)
 }
 
 // SetFrameless removes the window frame and title bar
 func (w *WebviewWindow) SetFrameless(frameless bool) *WebviewWindow {
 	w.options.Frameless = frameless
 	if w.impl != nil {
-		w.impl.setFrameless(frameless)
+		invokeSync(func() {
+			w.impl.setFrameless(frameless)
+		})
 	}
 	return w
 }
diff --git a/v3/pkg/application/webview_window_windows.go b/v3/pkg/application/webview_window_windows.go
index 671c3d4e5..b820abe9a 100644
--- a/v3/pkg/application/webview_window_windows.go
+++ b/v3/pkg/application/webview_window_windows.go
@@ -190,8 +190,8 @@ func (w *windowsWebviewWindow) enableSizeConstraints() {
 }
 
 func (w *windowsWebviewWindow) size() (int, int) {
-	//TODO implement me
-	panic("implement me")
+	rect := w32.GetWindowRect(w.hwnd)
+	return int(rect.Right - rect.Left), int(rect.Bottom - rect.Top)
 }
 
 func (w *windowsWebviewWindow) setForeground() {