There is a way to compare the contents in two sheet tabs in the same workbook. Lets see how this is done. In my example, Sheet1 has eleven rows, Sheet2 has ten rows. See following image:

This is for Excel for Office 365 Windows and Mac versions. Other versions of Excel will be similar.
Opening a Second Window for Comparing Contents
In the View tab of the Window group, click New Window

A second window of the same workbook opens, like a clone. At the end of the workbook name is a number denoting the sheet, either a one or a two. The new window becomes the active sheet.

Setting Up Side by Side Viewing
In the View tab of the Window group, click View Side by Side
A Compare Dialog box may appear. If so, choose the sheet you want to compare with the active sheet.
Click View Side by Side. When you select this view, Synchronous Scrolling should already be turned on. This allows you to scrool both worksheets at the same time. If its not turned on, click the View tab, then click Sychronous Scrolling. See below image:

If the two windows didn’t arrange side by side, from the View tab, click Arrange All>Vertical and check the box for Windows of active workbook. Refer to following image:

Viewing the Two Sheets Side by Side
You can now synchronously scroll both up and down, left and right to compare the contents of the two sheet tabs in the same workbook. See final image below:

When you are finished, to restore your window size, close one of the two windows, then click the Maximize Button in upper right hand corner of the worksheet window.
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