How to compare two Excel files

A useful Excel comparison starts by identifying the same record in both files. Once rows are matched correctly, changes are much easier to review.

Before you start

Keep one file as the old or baseline version and one as the new or updated version. Both files should have column names in the first row. Column order can differ, but names should be unique and non-empty.

Step-by-step

1. Add the old and new workbooks. Rowwise reads XLSX files in your browser. If a workbook has several sheets, select the sheet you want from each file.
2. Choose matching keys. Select one or more columns that identify the same logical row in both files.
3. Exclude irrelevant columns. Ignore timestamps, notes, or calculated fields that should remain visible but should not count as differences.
4. Add exceptions when needed. A directional exception can ignore one expected change, such as a status moving from “Pending” to “Approved”.
5. Compare and review. Filter the detailed results or switch to Old, New, or Side by side. In side-by-side mode, both sheets scroll together.
6. Export the evidence. Choose Excel for yellow-highlighted cells or CSV for a portable text result with status and changed-column labels.

What the comparison checks

Values are compared exactly, including case, whitespace, and data type. Blank cells are treated like empty strings. Workbook formatting is ignored, and formulas use the result saved in the file. If a column exists only in one file, it counts as a change on matched rows.

Common causes of unexpected results

If many rows appear New and Missing, the matching key may have changed between versions or may contain inconsistent spacing or types. If rows appear Duplicate, the selected key combination is not unique—or a row has an empty key. Resolve those key issues before treating the remaining result as final.