How to clean up a spreadsheet
- Drop in an .xlsx, .xls or .csv file. It is read on your own device.
- The sheet is scanned for the things that quietly break spreadsheets: numbers stored as text, dates left as serial numbers, duplicate rows, stray spaces.
- Untick anything you would rather keep, then press Clean.
- Download the repaired file as Excel, CSV or JSON.
Questions people ask
Why will my numbers not add up?
Almost always because they are stored as text rather than numbers. Excel will not include a text cell in a SUM, and it sorts such a column alphabetically — so 1000 lands before 9. It usually happens when data is pasted from a website, exported from an accounting system, or typed with a currency symbol or a space as a thousands separator. This tool finds those columns and converts them to real numbers, keeping negatives written as (450) and percentages as proper percentage values.
What is the number 45350 doing in my date column?
That is the date, as Excel actually stores it: a count of days since 1900. It shows as a number when the cell loses its date formatting, which commonly happens on export to CSV. The tool converts those back to real dates, but only in columns whose heading suggests a date, because the same number could legitimately be a quantity or a reference number elsewhere.
My headings are not in the first row. Will it still work?
Yes. Real spreadsheets often have a title, a logo row, or a block of report parameters above the actual column headings, and headings can be split across two or three stacked rows. The tool looks down the first 25 rows for the row that behaves like a header — short unique labels with data underneath — and treats everything above it as preamble, leaving it untouched.
Are my files uploaded anywhere?
No. The file is read and rewritten in your browser. Nothing is sent to a server.
Will it keep my formulas and formatting?
Formulas are left alone, and column widths and bold headings are applied to the output. Charts, images, pivot tables and macros are not carried across — if your workbook contains those, clean a copy and paste the corrected columns back, rather than replacing the original.
What counts as a duplicate row?
A row identical to an earlier row across every column, ignoring capitalisation and surrounding spaces. The first occurrence is kept and later ones removed. This is off by default, because in some registers a genuinely repeated line is meaningful — tick it only when you know duplicates are an error.
Can it handle a workbook with many sheets?
Yes. Every sheet is scanned and listed separately, so you can see which one has the problem and clean each on its own terms. The Excel download preserves all sheets; CSV and JSON export the sheet you are currently viewing, since neither format holds more than one table.