How to View and Compare Two Spreadsheets Side by Side with Synchronous Scrolling in Microsoft Excel

Cross-referencing financial models, auditing year-over-year ledger updates, and reconciling data between separate reporting sheets are fundamental tasks in Microsoft Excel. When comparing two datasets, repeatedly switching back and forth between different workbooks or workbook tabs is inefficient and prone to oversight. While standard Windows snap layouts allow you to place application windows side by side, Excel includes native viewing tools designed specifically to streamline comparative audits.

Through Excel’s built-in View Side by Side, Synchronous Scrolling, and New Window features, you can compare two completely independent workbooks—or even two different sheets within the exact same file—and scroll through rows and columns in lockstep. In this tutorial, you will master the configuration, navigation, and troubleshooting of side-by-side comparisons in Microsoft Excel.

Method 1: Comparing Two Separate Workbooks Side by Side

When you have two distinct workbook files—such as Q1_Sales.xlsx and Q2_Sales.xlsx—you can tile them horizontally or vertically and link their viewports within seconds.

1. Open both Excel workbooks on your computer.
2. Navigate to the ribbon and select the View tab.
3. In the Window group, click the View Side by Side button.
4. If you have more than two workbooks open simultaneously, Excel will present a Compare Side by Side dialogue box. Select the specific second workbook you wish to compare against and click OK.

Excel will instantly resize both workbook windows and tile them equally across your screen. By default, Excel arranges the windows horizontally (one above the other) or vertically (side by side), depending on your display resolution.

Method 2: Enabling and Using Synchronous Scrolling

Once View Side by Side is active, Excel automatically engages a complementary feature called Synchronous Scrolling.

• How Synchronous Scrolling Operates: When enabled, scrolling down with your mouse wheel or dragging the scroll bar in one workbook causes the adjacent workbook to scroll by the exact same number of rows and columns simultaneously. This allows you to verify line items side by side without manually repositioning each window.
• Aligning Starting Rows: For synchronous scrolling to work accurately, both workbooks must start at the same relative position. Before scrolling, click into each window and scroll both to row 1 (or your desired comparison header).
• Toggling Synchronous Scrolling On or Off: If you need to navigate to an appendix or reference table in one workbook without moving the second workbook, go to View > Window and click the Synchronous Scrolling button to disengage the link. Click it again once repositioned to re-engage synchronised movement.
• Reset Window Position: If you manually drag, resize, or minimise one of the windows, click Reset Window Position in the Window group on the View tab to immediately restore the balanced split-screen layout.

Method 3: Comparing Two Sheets in the Same Workbook Side by Side

A common operational challenge arises when you need to compare two different tabs inside a single workbook (for example, comparing an Inputs worksheet against a Summary worksheet). Because a single workbook normally opens in one window, clicking View Side by Side is initially greyed out. You can resolve this using Excel’s New Window command:

1. Open the workbook containing the multiple worksheets you want to compare.
2. Click on the View tab on the ribbon.
3. In the Window group, click New Window.
4. Notice the title bar at the top of your screen: Excel has opened a second visual instance of your workbook. The windows will now be titled WorkbookName:1 and WorkbookName:2.
5. With the second window open, return to the View tab and click View Side by Side.
6. In the left (or upper) window, click on your first worksheet tab (e.g., January). In the right (or lower) window, click on your second worksheet tab (e.g., February).

Both sheets are now displayed simultaneously with Synchronous Scrolling active. Because both windows represent live views into the identical underlying document, any edit, formula update, or formatting change made in WorkbookName:1 appears instantaneously in WorkbookName:2.

When you complete your comparison, simply click the Close (X) button on the secondary window (:2). Your primary window (:1) will revert to its standard single-file title, preserving all edits without creating duplicate files on your disk.

Customising Window Layouts with Arrange All

If you prefer a vertical split (left and right) rather than a horizontal split (top and bottom), or if you are using dual monitors, customise your layout using the Arrange All dialog:

1. On the View tab, click Arrange All.
2. Choose your preferred layout:
   • Tiled: Divides available desktop space evenly into equal tiles.
   • Horizontal: Stacks windows vertically one above the other (ideal for wide financial tables with many columns).
   • Vertical: Places windows side by side (ideal for tall datasets with hundreds of rows).
   • Cascade: Layers windows diagonally with visible title bars.
3. If you are working with multiple workbooks but only want to tile windows belonging to the current file, check the box labelled Windows of active workbook.
4. Click OK to apply the layout.

Troubleshooting Common Side-by-Side Viewing Issues

• Synchronous Scrolling Button is Greyed Out: The Synchronous Scrolling button only becomes clickable when View Side by Side is already turned on. Ensure that at least two workbook windows are actively open and that View Side by Side is toggled on.
• Rows Become Desynchronised: If one workbook contains title banners, merged header rows, or hidden rows that do not exist in the second workbook, rows will slowly drift out of alignment during scrolling. To fix this, align both workbooks to the first matching data row, turn off Synchronous Scrolling, align the cursors, and turn Synchronous Scrolling back on.
• Side-by-Side Mode Disappears: If you accidentally click the Maximise icon on either workbook window, Excel expands that window to full screen and pauses side-by-side mode. Simply click the Restore Down button or click Reset Window Position on the View tab to re-establish the split view.
• Frozen Panes Impeding Scroll: If one sheet has freeze panes enabled and the other does not, scrolling behaviour may appear inconsistent near the top of the sheet. Ensure freeze pane rules are standardised across both sheets under View > Freeze Panes.

Frequently Asked Questions

Can I edit data in both sheets while viewing them side by side?

Yes. Both windows are fully interactive and editable. You can write formulas, enter values, format cells, and copy ranges between both views just as you would in a standard single-window session.

Does closing the secondary window (:2) prompt me to save changes?

No. Excel understands that :2 is an auxiliary viewport of the same in-memory workbook. Closing :2 simply dismisses the additional window view. You will only be prompted to save your work when closing the final remaining workbook window (:1).

Can I use Synchronous Scrolling across two physical monitors?

By default, Excel tiles windows within its main application frame. However, you can drag WorkbookName:2 onto your second monitor and arrange both windows side by side across physical screens. As long as Synchronous Scrolling remains toggled on in the View ribbon, scrolling on either display will move both viewports in tandem.

Can I synchronously scroll three or more workbooks at the same time?

No. Excel’s native Synchronous Scrolling mechanism is engineered to link exactly two windows at any one time. If you open three or more workbooks and arrange them via Arrange All, scrolling in one window will not synchronise across all three simultaneously.