Local by design
The selected files are read in the browser instead of being handed to a separate upload workflow.
Privacy-first search
Compare Excel files without uploading them
Some people do not want a cloud workflow at all. This page answers that intent directly: the workbook comparison runs in the browser, and the selected files stay local during the comparison workflow.
What the page promises
Show the privacy boundary before the user starts the task
Useful for sensitive sheets
That makes the page relevant for internal budgets, operational checks, and private client workbooks.
Still a real diff tool
Privacy is the hook, but the output still has to be a useful workbook comparison result.
Honest limits
This does not mean every Excel format is supported. It is still a focused `.xlsx` comparison tool.
If the person only wants a CSV evidence trail, the export page is usually the better next click.
Fit check before you start
Use WorkbookDiff when the workbook layout stayed aligned
Good fit
Two `.xlsx` versions of the same workbook, with the same sheet names and mostly stable row and column positions. You want to see changed values, formulas, sheet state, or hidden rows and columns.
Private workflow
The files are read in browser memory. Workbook bytes are not uploaded by the comparison workflow, and the result can be exported as a CSV review record.
Not a row matcher
If rows were reordered or you need to match records by invoice number, employee ID, or another key, this is the wrong tool. Use a key-based reconciliation workflow instead.
Not every Excel format
The current tool supports `.xlsx` up to 20 MB per file. It does not accept `.xls`, `.xlsm`, `.xlsb`, CSV, ODS, or password-protected workbooks.
This fit check is intentionally narrow: a qualified user who completes a comparison is more valuable than a high bounce from a broad “Excel diff” claim.