Clean each worksheet, review changes as you make them, then download one approved workbook.
This app needs an HTTP or HTTPS address. Opening index.html directly with file:// cannot start the processing worker. Use the local preview server described in DEPLOYMENT.md, then open http://127.0.0.1:4173, or use the hosted HTTPS site.
Choose an Excel or CSV file
Drop one file here, or browse your device.
Help & privacy
Review each worksheet
Open each worksheet, choose its own corrections and headings, then approve it. Switching sheets keeps your edits. Editing a sheet invalidates only its approval. One download becomes available when every sheet is approved, including unchanged or empty sheets.
Inspect live changes
Choose a correction on the left and inspect the adjacent previews. Use the change arrows to jump to affected cells or headings. “Show changed rows only” filters the preview; it never filters the export.
Private browser processing
Spreadsheet contents stay in this browser. No uploads, cloud AI, analytics, accounts or persistent content storage are used. Site hosting receives ordinary page and sample-file requests only. Clear file removes data from this app; downloaded files remain on your device.
Data-table export
Every reviewed worksheet is exported in its original order with its original sheet name. Formula cells become literal text. Formatting, links, charts, macros and advanced workbook features are not preserved. UTF-8 CSV is supported as one worksheet; CSV dates are not guessed.
Limits and sensitive values
XLSX or UTF-8 CSV up to 10 MB, 100 worksheets, 50,000 rows, 200 columns and 500,000 cells per sheet. ZIP expansion and 30-second processing limits also apply. Dates from XLSX remain dates. Leading-zero text remains text; only simple all-zero numeric masks are protected as displayed text. Numeric-fill eligibility is conservative and needs your review. Resource limits reduce risk but are not a hostile-file sandbox. Use a current browser.
Review and approve each worksheet. Then download the complete workbook once.
CURRENT WORKSHEET
Original worksheet overview
1. Choose corrections
Choose what to fix. The preview updates as you work.
Worksheet notes & cleaning order
Order: headings, trim, remove duplicates, calculate medians, fill blanks. Missing means empty or whitespace-only. New duplicates created by filling remain. First row is headings; hidden rows and columns are included. CSV known values stay text.
4. Review and approve
Formulas become literal text. Formatting, charts, macros and advanced features are not preserved.
LIVE COMPARISON
Before & after
Changed Removed
Select a correction to see its effect here.
Before — Original data
After — Your changes
Change summary
More preview details
Rows align by their source row number. Blank cells are labeled. Tables scroll independently; headings stay visible.
