Spreadsheet Cleaner
Open a CSV or Excel file, choose cleaning steps, review the first 50 rows, and download the cleaned sheet.
Free, browser only — your file never leaves this browser.
Open your spreadsheet
Drop a CSV or XLSX file here, or choose a file.
Excel import uses displayed values. Downloads contain only the current sheet as text values, without formulas or formatting.
Cleaning steps
Applied in this order. For multiple columns, use Ctrl / Command + click on desktop, or the selection menu on your phone. Column choices refer to the preview before applying.
Counts add cell edits across steps. Column choices clear after applying because the table may have changed shape.
Preview
Excel support: SheetJS Community Edition 0.20.3, Apache-2.0 license.
Frequently asked questions
Does my file leave this browser?
Your file never leaves the device. CSV and Excel files are read and cleaned in this browser. The cleaner makes no network requests and needs no account.
How are dates fixed?
Choose MDY or DMY for numeric dates such as 03/04/2026. Year-first dates are also accepted. Dates become YYYY-MM-DD; invalid dates stay unchanged and are counted. Blank cells are skipped.
What happens to formulas and multiple sheets?
Import reads displayed cell values. Export contains plain text values for the selected sheet only; formulas, formatting, charts and macros are not retained. Each sheet keeps its own edits during this visit.
In what order are changes applied?
Steps run from top to bottom: trim, remove blanks, remove duplicates, change case, fix dates, split, then merge. Column choices refer to the current preview before applying. Reset restores the imported sheet. Counts add cell edits across steps, so a cell edited twice counts twice.
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