What This Tool Does
Load Workbook A and Workbook B in .xlsx, .xlsm, .xls, .xlsb, or .ods format. Sheets are matched by name. The result reports added and removed sheets, then compares common sheets for dimensions, headers, rows, and cells.
Sheet Matching and Ignore Rules
Sheets are matched by name, regardless of tab order. A sheet found in only one workbook is reported as added or removed and is not compared cell by cell. Use Ignore sheet(s) to skip sheets by name. Use Ignore column(s) to skip columns by header name, column letter, or 1-based index.
Choose a Cell Matching Mode
- Coordinate (match by cell position) compares A1 with A1, B2 with B2, and so on. Use it when both sheets keep the same layout.
- Key column(s) (match rows by value) matches rows using one or more key columns entered by header name, letter, or 1-based index. It then compares non-key columns whose header names match. Inserted, deleted, or reordered rows can still be matched by key value.
Key-column mode always treats row 1 as the header. If a specified key column is not found in a sheet's header row, that sheet is skipped for row-level comparison and a warning is shown. Duplicate key values are matched in order of appearance and also produce a warning.
Choose What to Compare
The default comparison uses displayed values. Turn on Compare formulas to check formula text as well. Turn on Compare cell formatting (number format) to check number-format differences.
First row is a header controls header handling in coordinate mode. Key-column mode always uses row 1 as its header. Ignore case and Ignore whitespace affect text normalization and key matching. Numeric-aware comparison affects displayed-value comparison; it is not used to construct keys.
Review Results and Export Reports
The summary shows added, removed, and compared sheets with aggregate counts. Coordinate mode displays a highlighted grid: green for added cells, red for removed cells, and amber for changed cells. The visible grid is limited to the first 60 rows and 30 columns. Key mode shows added, removed, and changed row lists, with before/after values where available; each list displays at most 500 items.
Use Export CSV or Export JSON. Coordinate-mode exports include changed-cell details. In key mode, JSON added and removed entries contain row numbers and keys rather than full row values. The CSV leaves before and after blank for those added or removed rows.
How to Use Spreadsheet Diff
- Load both workbooks through the Workbook A and Workbook B drop zones or their browse files controls.
- Select Coordinate (match by cell position) or Key column(s) (match rows by value).
- If using key mode, enter at least one key column name, letter, or index.
- Set Ignore sheet(s), Ignore column(s), and the comparison checkboxes as needed.
- Once both workbooks are ready, the comparison updates automatically. Change any setting to recompute the current report.
- Review the per-sheet results, then use Export CSV or Export JSON.
Troubleshooting and Confirmed Limitations
- Load both workbooks to start an automatic comparison. Key mode also requires at least one key column; change the matching mode or enter a key to recover.
.csv,.tsv, and.txtfiles are rejected as delimited text files; use CSV Diff for those files. Unrecognized extensions are rejected too.- A corrupt or password-protected workbook may fail to load. If the spreadsheet engine fails to load, check the connection and reload the page.
- The tool does not compare nested JSON paths; use JSON Diff for that structure.
- The implementation does not state a general usage, file-size, workbook-size, or browser-compatibility limit.
Privacy and File Handling
Workbooks are read locally with the browser File API. The implementation does not upload the files to a server, and it does not modify the source workbooks.
Frequently Asked Questions
How are sheets matched between the two workbooks?
Sheets are matched by name. Sheets present in only one workbook are reported as added or removed; sheets with matching names in both workbooks are compared in detail for dimensions, headers, and cells.
What's the difference between key-column and coordinate matching?
Coordinate matching compares cell A1 to A1, B2 to B2, and so on by position - useful when both sheets keep the same layout. Key-column matching treats the first row as a header, matches rows by the value in one or more chosen key columns, and then compares the remaining common columns for each matched row - so inserted, deleted, or reordered rows don't throw off the comparison.
Does this compare formulas or just displayed values?
By default it compares displayed values. Turn on Compare formulas to also flag cells whose formula text differs even if the calculated value matches. Turn on Compare cell formatting (number format) to flag differing number formats.
Why is CSV Diff or JSON Diff not used for this?
Converting a workbook to CSV throws away sheet boundaries, formulas, and cell formatting - CSV Diff intentionally only handles flat delimited tables. JSON Diff compares nested JSON document paths, which is a different structure entirely. Spreadsheet Diff reads the workbook format directly so multi-sheet structure, formulas, and displayed values are compared as they actually exist in the file.
Does this tool upload my files anywhere?
No. Files are read locally in your browser and compared entirely client-side. Nothing is uploaded, and neither original file is modified.