diff --git a/packages/notebook/src/browser/view-model/notebook-model.ts b/packages/notebook/src/browser/view-model/notebook-model.ts
index a80ce44e4e4ea..b007e1a793490 100644
--- a/packages/notebook/src/browser/view-model/notebook-model.ts
+++ b/packages/notebook/src/browser/view-model/notebook-model.ts
@@ -289,6 +289,10 @@ export class NotebookModel implements Saveable, Disposable {
         }
     }
 
+    getVisibleCells(): NotebookCellModel[] {
+        return this.cells;
+    }
+
     applyEdits(rawEdits: CellEditOperation[], computeUndoRedo: boolean): void {
         const editsWithDetails = rawEdits.map((edit, index) => {
             let cellIndex: number = -1;
diff --git a/packages/notebook/src/browser/view/notebook-cell-list-view.tsx b/packages/notebook/src/browser/view/notebook-cell-list-view.tsx
index 7753a74e97f3b..39eeada382d0d 100644
--- a/packages/notebook/src/browser/view/notebook-cell-list-view.tsx
+++ b/packages/notebook/src/browser/view/notebook-cell-list-view.tsx
@@ -120,7 +120,7 @@ export class NotebookCellListView extends React.Component<CellListProps, Noteboo
 
     override render(): React.ReactNode {
         return <ul className='theia-notebook-cell-list' ref={this.cellListRef} onDragStart={e => this.onDragStart(e)}>
-            {this.props.notebookModel.cells
+            {this.props.notebookModel.getVisibleCells()
                 .map((cell, index) =>
                     <React.Fragment key={'cell-' + cell.handle}>
                         <NotebookCellDivider
diff --git a/packages/plugin-ext/src/main/browser/notebooks/renderers/cell-output-webview.tsx b/packages/plugin-ext/src/main/browser/notebooks/renderers/cell-output-webview.tsx
index 9100d5aba52a0..79aa098d41586 100644
--- a/packages/plugin-ext/src/main/browser/notebooks/renderers/cell-output-webview.tsx
+++ b/packages/plugin-ext/src/main/browser/notebooks/renderers/cell-output-webview.tsx
@@ -354,21 +354,27 @@ export class CellOutputWebviewImpl implements CellOutputWebview, Disposable {
             this.webviewWidget.show();
         }
 
+        const visibleCells = new Set(this.notebook.getVisibleCells().map(cell => cell.handle));
+
         const updateOutputMessage: OutputChangedMessage = {
             type: 'outputChanged',
-            changes: updates.map(update => ({
-                cellHandle: update.cellHandle,
-                newOutputs: update.newOutputs.map(output => ({
-                    id: output.outputId,
-                    items: output.outputs.map(item => ({ mime: item.mime, data: item.data.buffer })),
-                    metadata: output.metadata
-                })),
-                start: update.start,
-                deleteCount: update.deleteCount
-            }))
+            changes: updates
+                .filter(update => visibleCells.has(update.cellHandle))
+                .map(update => ({
+                    cellHandle: update.cellHandle,
+                    newOutputs: update.newOutputs.map(output => ({
+                        id: output.outputId,
+                        items: output.outputs.map(item => ({ mime: item.mime, data: item.data.buffer })),
+                        metadata: output.metadata
+                    })),
+                    start: update.start,
+                    deleteCount: update.deleteCount
+                }))
         };
 
-        this.webviewWidget.sendMessage(updateOutputMessage);
+        if (updateOutputMessage.changes.length > 0) {
+            this.webviewWidget.sendMessage(updateOutputMessage);
+        }
     }
 
     cellsChanged(cellEvents: NotebookContentChangedEvent[]): void {
@@ -382,11 +388,12 @@ export class CellOutputWebviewImpl implements CellOutputWebview, Disposable {
                     toIndex: event.newIdx + i,
                 } as CellsMoved)));
             } else if (event.kind === NotebookCellsChangeType.ModelChange) {
+                const visibleCells = new Set(this.notebook.getVisibleCells());
                 changes.push(...event.changes.map(change => ({
                     type: 'cellsSpliced',
                     start: change.start,
                     deleteCount: change.deleteCount,
-                    newCells: change.newItems.map(cell => cell.handle)
+                    newCells: change.newItems.filter(cell => visibleCells.has(cell as NotebookCellModel)).map(cell => cell.handle)
                 } as CellsSpliced)));
             }
         }
@@ -429,7 +436,7 @@ export class CellOutputWebviewImpl implements CellOutputWebview, Disposable {
 
         switch (message.type) {
             case 'initialized':
-                this.updateOutputs(this.notebook.cells.map(cell => ({
+                this.updateOutputs(this.notebook.getVisibleCells().map(cell => ({
                     cellHandle: cell.handle,
                     newOutputs: cell.outputs,
                     start: 0,