Why compare by key, not by row number
Two exports of the same spreadsheet rarely keep the same row order: someone sorts by name, a filter hides rows, new records are inserted in the middle. Comparing row 5 with row 5 then reports almost everything as changed. Matching rows by a column that identifies them (an employee ID, SKU, invoice number or email) avoids that. In the example, the rows are shuffled, yet the result is exactly one department change, one salary change, one person who left and one new starter.
How to use it
- Click Open file on each side and choose the two .xlsx workbooks. If they have several sheets, pick the sheet to compare.
- Or copy a range in Excel or Google Sheets (include the header row) and paste it; cells arrive tab-separated and are detected automatically.
- Choose the column under Match rows by. Pick one whose values are unique per row.
- Read the list of changes, or download it as CSV to keep as an audit trail.
Dates are shown as YYYY-MM-DD and numbers as Excel stored them, so a cell that merely displays differently (e.g. 0.5 vs 50%) is not counted as a change. Comparing exports rather than workbooks? Use CSV compare; for one column against another, compare lists.
Questions
How do I compare two Excel files for differences?
Open both .xlsx files here (or paste the cells from each sheet), pick the column that identifies a row, such as an ID or email, and the tool lists rows added, rows removed and every cell whose value changed. Rows can be in any order. If a workbook has several sheets, choose which sheet to compare from the drop-down.
Can I compare two sheets without uploading them?
Yes. The .xlsx file is unzipped and read inside your browser with the open-source read-excel-file library. Nothing is uploaded.
Does it compare formulas, formatting or colours?
No. It compares the values the cells hold, as Excel last saved them. Formulas are not re-calculated, and formatting, comments, colours and charts are ignored.
What about .xls, .ods or Numbers files?
Only .xlsx workbooks can be opened directly. Save older .xls, LibreOffice .ods or Apple Numbers files as .xlsx or CSV first, or copy the cells and paste them in.
How do I compare two columns in Excel itself?
For a quick check inside Excel, put =A2=B2 in a helper column to flag rows where the two columns differ, or =COUNTIF(B:B,A2)=0 to flag values in column A that are missing from column B. Excel's own Spreadsheet Compare (Inquire add-in) exists only in some Microsoft 365 Apps for enterprise editions on Windows.
Can I save the result?
Yes. Download differences (.csv) gives a list of every added row, removed row and changed cell with old and new values, which opens back in Excel.