Compare a CSV file with an Excel XLSX worksheet
One export is CSV and the other is Excel. Compare the fields they share, with a few checks for format differences.
Spreadsheet Comparison can compare a CSV file with a selected XLSX worksheet. Load one on each side, map equivalent columns and choose the field that identifies the same record. You do not have to convert both originals into the same file format first.
Start with one table, not the whole workbook
A CSV usually represents one table. An Excel workbook can contain several sheets, so select the sheet that corresponds to the CSV. A pivot summary or monthly totals sheet will not match a detailed transaction export.
Consider a synthetic CSV with columns order_id, city and total. The Excel sheet has Order Number, Delivery City and Order Total. Map those pairs explicitly. Mark the order identifier as the key and compare city and total as values. Read the header-mapping guide if several fields have similar names.
Check how each format represents values
CSV stores text fields. A workbook can carry cell types, formulas and display formatting. Two exported values that look similar in their source applications may arrive as different strings. For example, a date might be 2026-09-01 in the CSV and 01/09/2026 in the worksheet. Establish what the source means before changing it.
The workbook importer reads available formatted display strings and saved formula results. It does not recalculate formulas. Open, recalculate and save the workbook first if the comparison depends on current formula results. The Excel import guide covers the limits and saved-value behavior.
Inspect identifiers before running the full review
Use a known order as a spot check. Has 00081 stayed 00081? Did a long identifier turn into scientific notation? Is a blank field actually blank, or did the exporter write a placeholder such as NULL? These questions often explain a surprising result more quickly than changing mappings at random.
Separate field changes from missing records
After comparing, first review matched records whose values differ. Then review records found only in each file. Equal row counts do not guarantee that both files contain the same IDs. Different row counts may also be expected if one export applies an active-only filter.
Export the filtered report once you have checked the key and field meanings. Keep it with the original filenames, selected worksheet and any preparation notes. If you need a clean CSV working copy, preserve the XLSX original and check that the export did not omit the records you intended to compare.