diff --git a/Controls/PreviewPane.xaml b/Controls/PreviewPane.xaml
index 98b20fc..9f96054 100644
--- a/Controls/PreviewPane.xaml
+++ b/Controls/PreviewPane.xaml
@@ -71,6 +71,15 @@
                                            Visibility="{Binding BackgroundVisible, Converter={StaticResource BoolToVis}}"/>
                                     <Image Source="{Binding ActiveBackgroundImage}" Stretch="UniformToFill"/>
                                 </Grid>
+                                <!-- Privacy blur preview (2026-11-01): whatever is BENEATH a blur layer
+                                     is blurred, right here in the editor — not a hatched placeholder. Each
+                                     child is a rectangle/ellipse filled with a VisualBrush of the whole
+                                     BackdropLayer (the desktop + background art), clipped to the blur's
+                                     shape and blurred at the same strength the output uses. Hosted AFTER
+                                     the backdrop and BEFORE the element layers, which is the model's own
+                                     z-rule: the blur sits above the desktop and below the brand. -->
+                                <Canvas x:Name="BlurPreviewHost" Width="1920" Height="1080" IsHitTestVisible="False"/>
+
                                 <Image x:Name="TransitionOverlay" Width="1920" Height="1080" Stretch="Fill"
                                        IsHitTestVisible="False" Visibility="Collapsed"/>
                                 <Canvas x:Name="OverlayCanvas" Width="1920" Height="1080">
diff --git a/Controls/PreviewPane.xaml.cs b/Controls/PreviewPane.xaml.cs
index a8a480c..b501f7d 100644
--- a/Controls/PreviewPane.xaml.cs
+++ b/Controls/PreviewPane.xaml.cs
@@ -47,6 +47,7 @@ public partial class PreviewPane : UserControl
             newVm.PreviewTransition += PlayPreviewTransition;
             UpdateZoomBox();
             UpdateSelectedLayerZOrder();
+            HookBlurPreview();
         }
     }
 
@@ -737,4 +738,95 @@ public partial class PreviewPane : UserControl
         if (DataContext is MainViewModel vm) vm.ToggleSettingsDrawer();
         e.Handled = true;
     }
+
+    // ─── Privacy blur preview (2026-11-01) ───
+    // The editor has to show the blur it is about to bake into the output: "whatever is beneath the
+    // blur layer is blurred". Each blur becomes a rectangle/ellipse filled with a VisualBrush of the
+    // whole BackdropLayer (desktop + background art) sampled at that rect, with a BlurEffect at the
+    // same strength the compositor uses. The host canvas sits between the backdrop and the element
+    // layers, which is the model's own z-rule.
+    private MainViewModel? _blurVm;
+    private Scene? _blurScene;
+
+    private void HookBlurPreview()
+    {
+        if (_blurVm != null) _blurVm.PropertyChanged -= BlurViewModelChanged;
+        _blurVm = DataContext as MainViewModel;
+        if (_blurVm != null) _blurVm.PropertyChanged += BlurViewModelChanged;
+        HookBlurScene();
+    }
+
+    private void BlurViewModelChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
+    {
+        if (e.PropertyName is nameof(MainViewModel.StagedScene)) HookBlurScene();
+        else if (e.PropertyName is nameof(MainViewModel.ActiveBackgroundImage)
+                 or nameof(MainViewModel.BackgroundImage)) RebuildBlurPreview();
+    }
+
+    private void HookBlurScene()
+    {
+        if (_blurScene != null)
+        {
+            _blurScene.Elements.CollectionChanged -= BlurElementsChanged;
+            foreach (var element in _blurScene.Elements) element.PropertyChanged -= BlurElementChanged;
+        }
+
+        _blurScene = _blurVm?.StagedScene;
+
+        if (_blurScene != null)
+        {
+            _blurScene.Elements.CollectionChanged += BlurElementsChanged;
+            foreach (var element in _blurScene.Elements) element.PropertyChanged += BlurElementChanged;
+        }
+
+        RebuildBlurPreview();
+    }
+
+    private void BlurElementsChanged(object? sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
+    {
+        foreach (var element in e.OldItems?.OfType<SceneElement>() ?? System.Linq.Enumerable.Empty<SceneElement>())
+            element.PropertyChanged -= BlurElementChanged;
+        foreach (var element in e.NewItems?.OfType<SceneElement>() ?? System.Linq.Enumerable.Empty<SceneElement>())
+            element.PropertyChanged += BlurElementChanged;
+        RebuildBlurPreview();
+    }
+
+    private void BlurElementChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
+    {
+        if (sender is Source { IsBlur: true }) RebuildBlurPreview();
+    }
+
+    /// <summary>Rebuild one overlay shape per visible blur. Cheap by design: a handful of shapes,
+    /// and the VisualBrush samples the live backdrop so the preview keeps moving underneath.</summary>
+    private void RebuildBlurPreview()
+    {
+        if (BlurPreviewHost == null) return;
+        BlurPreviewHost.Children.Clear();
+        if (_blurScene == null) return;
+
+        foreach (var blur in _blurScene.Elements.OfType<Source>()
+                     .Where(s => s.IsBlur && s.IsVisible && s.Width > 0 && s.Height > 0))
+        {
+            var shape = new Rectangle
+            {
+                Width = blur.Width,
+                Height = blur.Height,
+                Fill = new VisualBrush(BackdropLayer)
+                {
+                    Viewbox = new Rect(blur.X, blur.Y, blur.Width, blur.Height),
+                    ViewboxUnits = BrushMappingMode.Absolute,
+                    Stretch = Stretch.Fill,
+                },
+                // 4..24 px at master scale, the same shape of curve the compositor's radius uses.
+                Effect = new BlurEffect { Radius = 4 + 20 * Math.Clamp(blur.BlurAmount, 0, 1), KernelType = KernelType.Gaussian },
+            };
+
+            if (blur.ClipShape == ClipShape.Round)
+                shape.Clip = new EllipseGeometry(new Rect(0, 0, blur.Width, blur.Height));
+
+            Canvas.SetLeft(shape, blur.X);
+            Canvas.SetTop(shape, blur.Y);
+            BlurPreviewHost.Children.Add(shape);
+        }
+    }
 }