Compare two Excel files for differences

The usual situations

• Two versions of one workbook. Someone sent back “v3_final_FINAL.xlsx” and you need to know what they touched.
• A recurring export. A stock list, payroll extract or customer list from a system that you download every week or month. You want what is new, what disappeared and what changed.
• A supplier or partner file. A new price list or catalogue against the one you loaded last time, before you load the new one.
• Before and after a clean-up. You (or a macro) de-duplicated, re-sorted or re-keyed a sheet and want proof that nothing else changed.

In all four, rows are the unit that matters. RowDiff pairs rows first (by a key column such as an ID, or by aligning them in order when there isn’t one) and only then compares the cells of each pair. That is why a re-sorted file doesn’t show up as “everything changed”.

Step by step

1. Open the files. Drop the older file on A and the newer one on B (or drop both at once). Excel .xlsx, .xlsm and older .xls files open, as do OpenDocument .ods and CSV or tab-separated text. Nothing is uploaded: the files are read by JavaScript in this tab.
2. Pick the sheets. Each workbook lists its sheets; choose the pair to compare. To compare a different pair, change the selection and the result updates.
3. Choose how rows are matched. A key column gives the clearest result. Without one, rows are aligned in order, and an inserted or deleted row is shown as just that, not as a cascade of changes.
4. Remove the noise. Set a number tolerance (for example 0.005 to ignore differences below half a penny), tick Ignore case and Ignore extra spaces when those differences don’t matter to you.
5. Read and filter. The summary counts are buttons: click changed to see only changed rows. Columns that exist in only one file are labelled at the top of the table and listed in the summary.
6. Export if you need to. The .xlsx report has a summary sheet, a Differences sheet (status, row numbers in each file, every column, changed cells highlighted with the old value in a note) and a Cell changes sheet with one line per changed cell, including the numeric difference. The CSV holds each differing row with the A and B value of every column side by side.

Compare your two files above

Values or formulas?

By default RowDiff compares the values you see. That answers “did the numbers change?”. Switch to Formulas to answer “did anyone edit the logic?”: a cell whose formula changed from =SUM(B2:B9) to =SUM(B2:B8) shows as changed even if both happen to give the same total today. Cells without formulas are still compared by value in formula mode. The switch is greyed out when neither file contains formulas (CSV files never do).

Dates, number formats and text that looks like a number

Excel stores dates as numbers with a date format, and RowDiff compares the stored value, so 15/03/2023 and 2023-03-15 displayed in two different formats are the same date. Text that is a plain number (4.50 in a CSV) is compared as the number 4.5, so a CSV export and an Excel file agree. Codes with leading zeros, like 00123, stay text, because those zeros usually matter.

Limits worth knowing

Formatting, comments, charts, pivot tables and macros are not compared; this is a data comparison. Very large workbooks are limited by your browser’s memory rather than by RowDiff. Up to 5,000 rows is free on screen; larger files and all downloads use a credit, one per pair of sheets.

Related: Compare two Excel sheets · Compare two CSV files · Excel compare tools, free and paid