diff --git a/base/src/test/user_model/test_batch_row_column_diff.rs b/base/src/test/user_model/test_batch_row_column_diff.rs
index 829e6d8..b8adbca 100644
--- a/base/src/test/user_model/test_batch_row_column_diff.rs
+++ b/base/src/test/user_model/test_batch_row_column_diff.rs
@@ -25,15 +25,14 @@ fn diff_invariant_insert_rows() {
     assert!(model.insert_rows(0, 5, 3).is_ok());
 
     let list = last_diff_list(&mut model);
-    assert_eq!(list.len(), 3);
-    for diff in list {
-        match diff {
-            Diff::InsertRow { sheet, row } => {
-                assert_eq!(sheet, 0);
-                assert_eq!(row, 5);
-            }
-            _ => panic!("Unexpected diff variant"),
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::InsertRows { sheet, row, count } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 3);
         }
+        _ => panic!("Unexpected diff variant"),
     }
 }
 
@@ -44,15 +43,18 @@ fn diff_invariant_insert_columns() {
 
     assert!(model.insert_columns(0, 2, 4).is_ok());
     let list = last_diff_list(&mut model);
-    assert_eq!(list.len(), 4);
-    for diff in list {
-        match diff {
-            Diff::InsertColumn { sheet, column } => {
-                assert_eq!(sheet, 0);
-                assert_eq!(column, 2);
-            }
-            _ => panic!("Unexpected diff variant"),
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::InsertColumns {
+            sheet,
+            column,
+            count,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*column, 2);
+            assert_eq!(*count, 4);
         }
+        _ => panic!("Unexpected diff variant"),
     }
 }
 
@@ -93,7 +95,7 @@ fn undo_redo_after_batch_delete() {
 
 #[test]
 fn diff_order_delete_rows() {
-    // Verifies that delete diffs are generated bottom-to-top
+    // Verifies that delete diffs are generated with all data preserved
     let base = new_empty_model();
     let mut model = UserModel::from_model(base);
 
@@ -105,18 +107,27 @@ fn diff_order_delete_rows() {
     assert!(model.delete_rows(0, 5, 5).is_ok());
 
     let list = last_diff_list(&mut model);
-    assert_eq!(list.len(), 5);
+    assert_eq!(list.len(), 1);
 
-    // Diffs should be in reverse order: 9, 8, 7, 6, 5
-    let mut expected_row = 9;
-    for diff in list {
-        match diff {
-            Diff::DeleteRow { row, .. } => {
-                assert_eq!(row, expected_row);
-                expected_row -= 1;
+    // Should have one bulk diff with all the row data
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 5);
+            assert_eq!(old_data.len(), 5);
+            // Verify the data was collected for each row
+            for (i, row_data) in old_data.iter().enumerate() {
+                let _expected_value = (5 + i).to_string();
+                assert!(row_data.data.contains_key(&1));
             }
-            _ => panic!("Unexpected diff variant"),
         }
+        _ => panic!("Unexpected diff variant"),
     }
 }
 
@@ -157,6 +168,7 @@ fn edge_case_single_operation() {
 
 #[test]
 fn delete_empty_rows() {
+    // Delete multiple empty rows and verify behavior
     let base = new_empty_model();
     let mut model = UserModel::from_model(base);
 
@@ -171,19 +183,26 @@ fn delete_empty_rows() {
     assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "Before");
     assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "After");
 
-    // Verify diffs are in reverse order with empty data
+    // Verify diffs now use bulk operation
     let list = last_diff_list(&mut model);
-    assert_eq!(list.len(), 4);
-    let mut expected_row = 8;
-    for diff in &list {
-        match diff {
-            Diff::DeleteRow { row, old_data, .. } => {
-                assert_eq!(*row, expected_row);
-                assert!(old_data.data.is_empty());
-                expected_row -= 1;
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 4);
+            assert_eq!(old_data.len(), 4);
+            // All rows should be empty
+            for row_data in old_data {
+                assert!(row_data.data.is_empty());
             }
-            _ => panic!("Unexpected diff variant"),
         }
+        _ => panic!("Unexpected diff variant"),
     }
 
     // Undo/redo
@@ -209,15 +228,28 @@ fn delete_mixed_empty_and_filled_rows() {
 
     // Verify mix of empty and filled row diffs
     let list = last_diff_list(&mut model);
-    assert_eq!(list.len(), 5);
-    let filled_count = list
-        .iter()
-        .filter(|diff| match diff {
-            Diff::DeleteRow { old_data, .. } => !old_data.data.is_empty(),
-            _ => false,
-        })
-        .count();
-    assert_eq!(filled_count, 3);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 5);
+            assert_eq!(*count, 5);
+            assert_eq!(old_data.len(), 5);
+
+            // Count filled rows (should be 3: rows 5, 7, 9)
+            let filled_count = old_data
+                .iter()
+                .filter(|row_data| !row_data.data.is_empty())
+                .count();
+            assert_eq!(filled_count, 3);
+        }
+        _ => panic!("Unexpected diff variant"),
+    }
 
     // Undo
     model.undo().unwrap();
@@ -227,6 +259,409 @@ fn delete_mixed_empty_and_filled_rows() {
     assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "After");
 }
 
+#[test]
+fn bulk_insert_rows_undo_redo() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up initial data
+    model.set_user_input(0, 1, 1, "A1").unwrap();
+    model.set_user_input(0, 2, 1, "A2").unwrap();
+    model.set_user_input(0, 5, 1, "A5").unwrap();
+
+    // Insert 3 rows at position 3
+    assert!(model.insert_rows(0, 3, 3).is_ok());
+
+    // Verify data has shifted
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 2, 1).unwrap(), "A2");
+    assert_eq!(model.get_formatted_cell_value(0, 8, 1).unwrap(), "A5"); // A5 moved to A8
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::InsertRows { sheet, row, count } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 3);
+            assert_eq!(*count, 3);
+        }
+        _ => panic!("Expected InsertRows diff"),
+    }
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "A5"); // Back to original position
+
+    // Redo
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 8, 1).unwrap(), "A5"); // Shifted again
+}
+
+#[test]
+fn bulk_insert_columns_undo_redo() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up initial data
+    model.set_user_input(0, 1, 1, "A1").unwrap();
+    model.set_user_input(0, 1, 2, "B1").unwrap();
+    model.set_user_input(0, 1, 5, "E1").unwrap();
+
+    // Insert 3 columns at position 3
+    assert!(model.insert_columns(0, 3, 3).is_ok());
+
+    // Verify data has shifted
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 2).unwrap(), "B1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 8).unwrap(), "E1"); // E1 moved to H1
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::InsertColumns {
+            sheet,
+            column,
+            count,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*column, 3);
+            assert_eq!(*count, 3);
+        }
+        _ => panic!("Expected InsertColumns diff"),
+    }
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 5).unwrap(), "E1"); // Back to original position
+
+    // Redo
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 8).unwrap(), "E1"); // Shifted again
+}
+
+#[test]
+fn bulk_delete_rows_round_trip() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data with styles
+    model.set_user_input(0, 3, 1, "Row3").unwrap();
+    model.set_user_input(0, 4, 1, "Row4").unwrap();
+    model.set_user_input(0, 5, 1, "Row5").unwrap();
+    model.set_user_input(0, 6, 1, "Row6").unwrap();
+    model.set_user_input(0, 7, 1, "After").unwrap();
+
+    // Set some row heights to verify they're preserved
+    model.set_rows_height(0, 4, 4, 30.0).unwrap();
+    model.set_rows_height(0, 5, 5, 40.0).unwrap();
+
+    // Delete rows 3-6
+    assert!(model.delete_rows(0, 3, 4).is_ok());
+
+    // Verify deletion
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "After");
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteRows {
+            sheet,
+            row,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*row, 3);
+            assert_eq!(*count, 4);
+            assert_eq!(old_data.len(), 4);
+            // Verify data was preserved
+            assert!(old_data[0].data.contains_key(&1)); // Row3
+            assert!(old_data[1].data.contains_key(&1)); // Row4
+            assert!(old_data[2].data.contains_key(&1)); // Row5
+            assert!(old_data[3].data.contains_key(&1)); // Row6
+        }
+        _ => panic!("Expected DeleteRows diff"),
+    }
+
+    // Undo - should restore all data and row heights
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "Row3");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 1).unwrap(), "Row4");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "Row5");
+    assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "Row6");
+    assert_eq!(model.get_formatted_cell_value(0, 7, 1).unwrap(), "After");
+    assert_eq!(model.get_row_height(0, 4).unwrap(), 30.0);
+    assert_eq!(model.get_row_height(0, 5).unwrap(), 40.0);
+
+    // Redo - should delete again
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "After");
+
+    // Final undo to verify round-trip
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 3, 1).unwrap(), "Row3");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 1).unwrap(), "Row4");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 1).unwrap(), "Row5");
+    assert_eq!(model.get_formatted_cell_value(0, 6, 1).unwrap(), "Row6");
+}
+
+#[test]
+fn bulk_delete_columns_round_trip() {
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data with styles
+    model.set_user_input(0, 1, 3, "C1").unwrap();
+    model.set_user_input(0, 1, 4, "D1").unwrap();
+    model.set_user_input(0, 1, 5, "E1").unwrap();
+    model.set_user_input(0, 1, 6, "F1").unwrap();
+    model.set_user_input(0, 1, 7, "After").unwrap();
+
+    // Set some column widths to verify they're preserved
+    model.set_columns_width(0, 4, 4, 100.0).unwrap();
+    model.set_columns_width(0, 5, 5, 120.0).unwrap();
+
+    // Delete columns 3-6
+    assert!(model.delete_columns(0, 3, 4).is_ok());
+
+    // Verify deletion
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "After");
+
+    // Check diff structure
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::DeleteColumns {
+            sheet,
+            column,
+            count,
+            old_data,
+        } => {
+            assert_eq!(*sheet, 0);
+            assert_eq!(*column, 3);
+            assert_eq!(*count, 4);
+            assert_eq!(old_data.len(), 4);
+            // Verify data was preserved
+            assert!(old_data[0].data.contains_key(&1)); // C1
+            assert!(old_data[1].data.contains_key(&1)); // D1
+            assert!(old_data[2].data.contains_key(&1)); // E1
+            assert!(old_data[3].data.contains_key(&1)); // F1
+        }
+        _ => panic!("Expected DeleteColumns diff"),
+    }
+
+    // Undo - should restore all data and column widths
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "C1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 4).unwrap(), "D1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 5).unwrap(), "E1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 6).unwrap(), "F1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 7).unwrap(), "After");
+    assert_eq!(model.get_column_width(0, 4).unwrap(), 100.0);
+    assert_eq!(model.get_column_width(0, 5).unwrap(), 120.0);
+
+    // Redo - should delete again
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "After");
+
+    // Final undo to verify round-trip
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 3).unwrap(), "C1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 4).unwrap(), "D1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 5).unwrap(), "E1");
+    assert_eq!(model.get_formatted_cell_value(0, 1, 6).unwrap(), "F1");
+}
+
+#[test]
+fn complex_bulk_operations_sequence() {
+    // Test a complex sequence of bulk operations
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Initial setup
+    model.set_user_input(0, 1, 1, "A1").unwrap();
+    model.set_user_input(0, 2, 2, "B2").unwrap();
+    model.set_user_input(0, 3, 3, "C3").unwrap();
+
+    // Operation 1: Insert 2 rows at position 2
+    model.insert_rows(0, 2, 2).unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 2).unwrap(), "B2"); // B2 moved down
+    assert_eq!(model.get_formatted_cell_value(0, 5, 3).unwrap(), "C3"); // C3 moved down
+
+    // Operation 2: Insert 2 columns at position 2
+    model.insert_columns(0, 2, 2).unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "A1");
+    assert_eq!(model.get_formatted_cell_value(0, 4, 4).unwrap(), "B2"); // B2 moved right
+    assert_eq!(model.get_formatted_cell_value(0, 5, 5).unwrap(), "C3"); // C3 moved right
+
+    // Operation 3: Delete the inserted rows
+    model.delete_rows(0, 2, 2).unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 2, 4).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 3, 5).unwrap(), "C3");
+
+    // Undo all operations
+    model.undo().unwrap(); // Undo delete rows
+    assert_eq!(model.get_formatted_cell_value(0, 4, 4).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 5).unwrap(), "C3");
+
+    model.undo().unwrap(); // Undo insert columns
+    assert_eq!(model.get_formatted_cell_value(0, 4, 2).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 5, 3).unwrap(), "C3");
+
+    model.undo().unwrap(); // Undo insert rows
+    assert_eq!(model.get_formatted_cell_value(0, 2, 2).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 3, 3).unwrap(), "C3");
+
+    // Redo all operations
+    model.redo().unwrap(); // Redo insert rows
+    model.redo().unwrap(); // Redo insert columns
+    model.redo().unwrap(); // Redo delete rows
+    assert_eq!(model.get_formatted_cell_value(0, 2, 4).unwrap(), "B2");
+    assert_eq!(model.get_formatted_cell_value(0, 3, 5).unwrap(), "C3");
+}
+
+#[test]
+fn bulk_operations_with_formulas_update() {
+    // Test that formulas update correctly with bulk operations
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data and formulas
+    model.set_user_input(0, 1, 1, "10").unwrap();
+    model.set_user_input(0, 5, 1, "20").unwrap();
+    model.set_user_input(0, 10, 1, "=A1+A5").unwrap(); // Formula referencing A1 and A5
+
+    // Insert 3 rows at position 3
+    model.insert_rows(0, 3, 3).unwrap();
+
+    // Formula should update to reference the shifted cells
+    assert_eq!(model.get_formatted_cell_value(0, 13, 1).unwrap(), "30"); // Formula moved down
+    assert_eq!(model.get_cell_content(0, 13, 1).unwrap(), "=A1+A8"); // A5 became A8
+
+    // Undo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 10, 1).unwrap(), "30");
+    assert_eq!(model.get_cell_content(0, 10, 1).unwrap(), "=A1+A5");
+
+    // Now test column insertion
+    model.set_user_input(0, 1, 5, "20").unwrap(); // Add value in E1
+    model.set_user_input(0, 1, 10, "=A1+E1").unwrap();
+    model.insert_columns(0, 3, 2).unwrap();
+
+    assert_eq!(model.get_formatted_cell_value(0, 1, 12).unwrap(), "30"); // Formula moved right
+    assert_eq!(model.get_cell_content(0, 1, 12).unwrap(), "=A1+G1"); // E1 became G1
+}
+
+#[test]
+fn bulk_delete_with_styles() {
+    // Test that cell and row/column styles are preserved
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Set up data with various styles
+    for r in 5..10 {
+        model.set_user_input(0, r, 1, &format!("Row{}", r)).unwrap();
+        model.set_rows_height(0, r, r, (r * 10) as f64).unwrap();
+    }
+
+    // Delete and verify style preservation
+    model.delete_rows(0, 5, 5).unwrap();
+
+    // Undo should restore all styles
+    model.undo().unwrap();
+    for r in 5..10 {
+        assert_eq!(
+            model.get_formatted_cell_value(0, r, 1).unwrap(),
+            format!("Row{}", r)
+        );
+        assert_eq!(model.get_row_height(0, r).unwrap(), (r * 10) as f64);
+    }
+}
+
+#[test]
+fn bulk_operations_large_count() {
+    // Test operations with large counts
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Insert a large number of rows
+    model.set_user_input(0, 1, 1, "Before").unwrap();
+    model.set_user_input(0, 100, 1, "After").unwrap();
+
+    assert!(model.insert_rows(0, 50, 100).is_ok());
+
+    // Verify shift
+    assert_eq!(model.get_formatted_cell_value(0, 1, 1).unwrap(), "Before");
+    assert_eq!(model.get_formatted_cell_value(0, 200, 1).unwrap(), "After"); // Moved by 100
+
+    // Check diff
+    let list = last_diff_list(&mut model);
+    assert_eq!(list.len(), 1);
+    match &list[0] {
+        Diff::InsertRows { count, .. } => {
+            assert_eq!(*count, 100);
+        }
+        _ => panic!("Expected InsertRows diff"),
+    }
+
+    // Undo and redo
+    model.undo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 100, 1).unwrap(), "After");
+
+    model.redo().unwrap();
+    assert_eq!(model.get_formatted_cell_value(0, 200, 1).unwrap(), "After");
+}
+
+#[test]
+fn bulk_operations_error_cases() {
+    // Test error conditions
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Negative count should fail
+    assert!(model.insert_rows(0, 1, -5).is_err());
+    assert!(model.insert_columns(0, 1, -5).is_err());
+    assert!(model.delete_rows(0, 1, -5).is_err());
+    assert!(model.delete_columns(0, 1, -5).is_err());
+
+    // Zero count should fail
+    assert!(model.insert_rows(0, 1, 0).is_err());
+    assert!(model.insert_columns(0, 1, 0).is_err());
+    assert!(model.delete_rows(0, 1, 0).is_err());
+    assert!(model.delete_columns(0, 1, 0).is_err());
+
+    // Out of bounds operations should fail
+    assert!(model.delete_rows(0, LAST_ROW - 5, 10).is_err());
+    assert!(model.delete_columns(0, LAST_COLUMN - 5, 10).is_err());
+}
+
+#[test]
+fn bulk_diff_serialization() {
+    // Test that bulk diffs can be serialized/deserialized correctly
+    let base = new_empty_model();
+    let mut model = UserModel::from_model(base);
+
+    // Create some data
+    model.set_user_input(0, 1, 1, "Test").unwrap();
+    model.insert_rows(0, 2, 3).unwrap();
+
+    // Flush and get the serialized diffs
+    let bytes = model.flush_send_queue();
+
+    // Create a new model and apply the diffs
+    let base2 = new_empty_model();
+    let mut model2 = UserModel::from_model(base2);
+
+    assert!(model2.apply_external_diffs(&bytes).is_ok());
+
+    // Verify the state matches
+    assert_eq!(model2.get_formatted_cell_value(0, 1, 1).unwrap(), "Test");
+}
+
 #[test]
 fn boundary_validation() {
     let base = new_empty_model();
diff --git a/base/src/user_model/common.rs b/base/src/user_model/common.rs
index c975649..c99589c 100644
--- a/base/src/user_model/common.rs
+++ b/base/src/user_model/common.rs
@@ -874,10 +874,11 @@ impl UserModel {
     pub fn insert_rows(&mut self, sheet: u32, row: i32, row_count: i32) -> Result<(), String> {
         self.model.insert_rows(sheet, row, row_count)?;
 
-        let mut diff_list = Vec::new();
-        for _ in 0..row_count {
-            diff_list.push(Diff::InsertRow { sheet, row });
-        }
+        let diff_list = vec![Diff::InsertRows {
+            sheet,
+            row,
+            count: row_count,
+        }];
         self.push_diff_list(diff_list);
         self.evaluate_if_not_paused();
         Ok(())
@@ -903,10 +904,11 @@ impl UserModel {
     ) -> Result<(), String> {
         self.model.insert_columns(sheet, column, column_count)?;
 
-        let mut diff_list = Vec::new();
-        for _ in 0..column_count {
-            diff_list.push(Diff::InsertColumn { sheet, column });
-        }
+        let diff_list = vec![Diff::InsertColumns {
+            sheet,
+            column,
+            count: column_count,
+        }];
         self.push_diff_list(diff_list);
         self.evaluate_if_not_paused();
         Ok(())
@@ -921,9 +923,9 @@ impl UserModel {
     /// See also [`Model::delete_rows`].
     pub fn delete_rows(&mut self, sheet: u32, row: i32, row_count: i32) -> Result<(), String> {
         let worksheet = self.model.workbook.worksheet(sheet)?;
-        let mut diff_list = Vec::new();
-        // Bottom to top order prevents index drift during undo
-        for r in (row..row + row_count).rev() {
+        let mut old_data = Vec::new();
+        // Collect data for all rows to be deleted
+        for r in row..row + row_count {
             let mut row_data = None;
             for rd in &worksheet.rows {
                 if rd.r == r {
@@ -935,18 +937,20 @@ impl UserModel {
                 Some(s) => s.clone(),
                 None => HashMap::new(),
             };
-            diff_list.push(Diff::DeleteRow {
-                sheet,
-                row: r,
-                old_data: Box::new(RowData {
-                    row: row_data,
-                    data,
-                }),
+            old_data.push(RowData {
+                row: row_data,
+                data,
             });
         }
 
         self.model.delete_rows(sheet, row, row_count)?;
 
+        let diff_list = vec![Diff::DeleteRows {
+            sheet,
+            row,
+            count: row_count,
+            old_data,
+        }];
         self.push_diff_list(diff_list);
         self.evaluate_if_not_paused();
         Ok(())
@@ -966,9 +970,9 @@ impl UserModel {
         column_count: i32,
     ) -> Result<(), String> {
         let worksheet = self.model.workbook.worksheet(sheet)?;
-        let mut diff_list = Vec::new();
-        // Right to left order prevents index drift during undo
-        for c in (column..column + column_count).rev() {
+        let mut old_data = Vec::new();
+        // Collect data for all columns to be deleted
+        for c in column..column + column_count {
             let mut column_data = None;
             for col in &worksheet.cols {
                 if c >= col.min && c <= col.max {
@@ -990,18 +994,20 @@ impl UserModel {
                 }
             }
 
-            diff_list.push(Diff::DeleteColumn {
-                sheet,
-                column: c,
-                old_data: Box::new(ColumnData {
-                    column: column_data,
-                    data,
-                }),
+            old_data.push(ColumnData {
+                column: column_data,
+                data,
             });
         }
 
         self.model.delete_columns(sheet, column, column_count)?;
 
+        let diff_list = vec![Diff::DeleteColumns {
+            sheet,
+            column,
+            count: column_count,
+            old_data,
+        }];
         self.push_diff_list(diff_list);
         self.evaluate_if_not_paused();
         Ok(())
@@ -2001,6 +2007,7 @@ impl UserModel {
     fn apply_undo_diff_list(&mut self, diff_list: &DiffList) -> Result<(), String> {
         let mut needs_evaluation = false;
         for diff in diff_list.iter().rev() {
+            #[allow(deprecated)]
             match diff {
                 Diff::SetCellValue {
                     sheet,
@@ -2121,6 +2128,58 @@ impl UserModel {
                         worksheet.set_column_width_and_style(*column, width, style)?;
                     }
                 }
+                Diff::InsertRows { sheet, row, count } => {
+                    self.model.delete_rows(*sheet, *row, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::DeleteRows {
+                    sheet,
+                    row,
+                    count: _,
+                    old_data,
+                } => {
+                    needs_evaluation = true;
+                    self.model
+                        .insert_rows(*sheet, *row, old_data.len() as i32)?;
+                    let worksheet = self.model.workbook.worksheet_mut(*sheet)?;
+                    for (i, row_data) in old_data.iter().enumerate() {
+                        let r = *row + i as i32;
+                        if let Some(row_style) = row_data.row.clone() {
+                            worksheet.rows.push(row_style);
+                        }
+                        worksheet.sheet_data.insert(r, row_data.data.clone());
+                    }
+                }
+                Diff::InsertColumns {
+                    sheet,
+                    column,
+                    count,
+                } => {
+                    self.model.delete_columns(*sheet, *column, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::DeleteColumns {
+                    sheet,
+                    column,
+                    count: _,
+                    old_data,
+                } => {
+                    needs_evaluation = true;
+                    self.model
+                        .insert_columns(*sheet, *column, old_data.len() as i32)?;
+                    let worksheet = self.model.workbook.worksheet_mut(*sheet)?;
+                    for (i, col_data) in old_data.iter().enumerate() {
+                        let c = *column + i as i32;
+                        for (row, cell) in &col_data.data {
+                            worksheet.update_cell(*row, c, cell.clone())?;
+                        }
+                        if let Some(col) = &col_data.column {
+                            let width = col.width * constants::COLUMN_WIDTH_FACTOR;
+                            let style = col.style;
+                            worksheet.set_column_width_and_style(c, width, style)?;
+                        }
+                    }
+                }
                 Diff::SetFrozenRowsCount {
                     sheet,
                     new_value: _,
@@ -2288,6 +2347,7 @@ impl UserModel {
     fn apply_diff_list(&mut self, diff_list: &DiffList) -> Result<(), String> {
         let mut needs_evaluation = false;
         for diff in diff_list {
+            #[allow(deprecated)]
             match diff {
                 Diff::SetCellValue {
                     sheet,
@@ -2368,6 +2428,36 @@ impl UserModel {
                     self.model.delete_columns(*sheet, *column, 1)?;
                     needs_evaluation = true;
                 }
+                Diff::InsertRows { sheet, row, count } => {
+                    self.model.insert_rows(*sheet, *row, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::DeleteRows {
+                    sheet,
+                    row,
+                    count,
+                    old_data: _,
+                } => {
+                    self.model.delete_rows(*sheet, *row, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::InsertColumns {
+                    sheet,
+                    column,
+                    count,
+                } => {
+                    self.model.insert_columns(*sheet, *column, *count)?;
+                    needs_evaluation = true;
+                }
+                Diff::DeleteColumns {
+                    sheet,
+                    column,
+                    count,
+                    old_data: _,
+                } => {
+                    self.model.delete_columns(*sheet, *column, *count)?;
+                    needs_evaluation = true;
+                }
                 Diff::SetFrozenRowsCount {
                     sheet,
                     new_value,
diff --git a/base/src/user_model/history.rs b/base/src/user_model/history.rs
index 53268e1..de2514f 100644
--- a/base/src/user_model/history.rs
+++ b/base/src/user_model/history.rs
@@ -1,3 +1,5 @@
+#![allow(deprecated)]
+
 use std::collections::HashMap;
 
 use bitcode::{Decode, Encode};
@@ -17,6 +19,7 @@ pub(crate) struct ColumnData {
 }
 
 #[derive(Clone, Encode, Decode)]
+#[allow(deprecated)]
 pub(crate) enum Diff {
     // Cell diffs
     SetCellValue {
@@ -87,23 +90,83 @@ pub(crate) enum Diff {
         row: i32,
         old_value: Box<Option<Style>>,
     },
+    /// **DEPRECATED**: Use `InsertRows` with count=1 instead.
+    ///
+    /// This variant is kept for backward compatibility to handle old persisted diffs.
+    /// New code should always use `InsertRows` even for single row insertions.
+    #[deprecated(since = "0.5.0", note = "Use InsertRows with count=1 instead")]
+    #[allow(dead_code)]
+    #[allow(deprecated)]
     InsertRow {
+        #[allow(deprecated)]
         sheet: u32,
+        #[allow(deprecated)]
         row: i32,
     },
+    /// **DEPRECATED**: Use `DeleteRows` with count=1 instead.
+    ///
+    /// This variant is kept for backward compatibility to handle old persisted diffs.
+    /// New code should always use `DeleteRows` even for single row deletions.
+    #[deprecated(since = "0.5.0", note = "Use DeleteRows with count=1 instead")]
+    #[allow(dead_code)]
+    #[allow(deprecated)]
     DeleteRow {
+        #[allow(deprecated)]
         sheet: u32,
+        #[allow(deprecated)]
         row: i32,
+        #[allow(deprecated)]
         old_data: Box<RowData>,
     },
+    /// **DEPRECATED**: Use `InsertColumns` with count=1 instead.
+    ///
+    /// This variant is kept for backward compatibility to handle old persisted diffs.
+    /// New code should always use `InsertColumns` even for single column insertions.
+    #[deprecated(since = "0.5.0", note = "Use InsertColumns with count=1 instead")]
+    #[allow(dead_code)]
+    #[allow(deprecated)]
     InsertColumn {
+        #[allow(deprecated)]
         sheet: u32,
+        #[allow(deprecated)]
         column: i32,
     },
+    /// **DEPRECATED**: Use `DeleteColumns` with count=1 instead.
+    ///
+    /// This variant is kept for backward compatibility to handle old persisted diffs.
+    /// New code should always use `DeleteColumns` even for single column deletions.
+    #[deprecated(since = "0.5.0", note = "Use DeleteColumns with count=1 instead")]
+    #[allow(dead_code)]
+    #[allow(deprecated)]
     DeleteColumn {
+        #[allow(deprecated)]
+        sheet: u32,
+        #[allow(deprecated)]
+        column: i32,
+        #[allow(deprecated)]
+        old_data: Box<ColumnData>,
+    },
+    InsertRows {
+        sheet: u32,
+        row: i32,
+        count: i32,
+    },
+    DeleteRows {
+        sheet: u32,
+        row: i32,
+        count: i32,
+        old_data: Vec<RowData>,
+    },
+    InsertColumns {
         sheet: u32,
         column: i32,
-        old_data: Box<ColumnData>,
+        count: i32,
+    },
+    DeleteColumns {
+        sheet: u32,
+        column: i32,
+        count: i32,
+        old_data: Vec<ColumnData>,
     },
     DeleteSheet {
         sheet: u32,