Clean a messy Excel file — no CSV conversion needed
An XLSX workbook picks up its own mess over time: duplicate rows from merged sheets, inconsistent name casing, date formats that drift the moment more than one person touches the file, and numbers typed a dozen different ways. DataMadeClean cleans the workbook directly and records every change for you to review — no need to export to CSV first.
No account needed · .xlsx files · no CSV conversion needed
Before you upload a workbook
DataMadeClean cleans the first worksheet and returns the cleaned data as a new .xlsx. Sheets after the first are not included in the file you download.
Formulas and visual formatting are not carried over either — the cleaned file holds values, not a rebuilt workbook. Keep your original if those matter, and clean the data sheet on its own.
What a workbook looks like after a few hands touch it
None of this is unique to Excel, but a shared workbook accumulates it faster than a one-off CSV export.
- Duplicate rows left over from a copy-pasted range or a merged sheet
- Inconsistent capitalization from manual entry — "john smith" vs "John Smith" vs "JOHN SMITH"
- Stray whitespace and blank padding left over from pasted values
- Mixed date formats in the same column — Excel's own date formatting menu makes this worse, not better, once more than one person has edited the file
- Currency and number values typed inconsistently — "$1,204.50" next to "1204.5"
- Phone numbers entered in different formats across the same contact list
Before / after
The same workbook, cleaned
Before
| Customer | Order date | Total |
|---|---|---|
| john smith | 13/04/2026 | $1,204.50 |
| John Smith | 2026-04-13 | 1,204.5 |
| JOHN SMITH | April 13, 2026 | 1204.5 |
After
| Customer | Order date | Total |
|---|---|---|
| John Smith | 2026-04-13 | 1204.50 |
| duplicate — removed | ||
| duplicate — removed | ||
Illustrative output with ISO date format selected. Name casing, whitespace and numeric values are normalised before duplicate rows are removed. Matching requires agreement across every column after cleaning.
How DataMadeClean handles it
Upload, review, download
Upload your workbook
Drag and drop an .xlsx file — no account needed to try it, and no need to save it as a CSV first.
Automatic detection
DataMadeClean identifies column types — names, emails, dates, phone numbers — straight from the workbook.
Review the changes
See a before/after summary — what was deduplicated, reformatted, or flagged as incomplete.
Download the clean file
Get back a workbook in the same structure you uploaded, ready to import anywhere.
Your file is only ever used to clean it. An anonymous upload and its result are deleted an hour after cleaning; signed in, results follow your account's retention setting.
Got a workbook that three people have edited?
Clean a workbook free →Questions
Before you clean an Excel workbook
Can I clean an Excel file without converting it to CSV first?
Yes. An .xlsx workbook is read directly and you get an .xlsx back, so there is no conversion to CSV in either direction. What the cleaned workbook does not carry over is covered below: formulas, cell formatting, and any sheet after the first.
What does it change in a spreadsheet?
Stray whitespace and invisible characters, casing on personal names, email addresses lowercased, phone numbers and dates brought to one format per column, number formatting, and duplicate rows. Every change is listed individually, so nothing is altered without you being able to see exactly what it was and what it became.
Will it strip leading zeros the way Excel does?
No. Excel drops them when it decides a column of digit strings is numbers; here the column is read as text, so a zero-padded customer ID, product code or postcode keeps its zeros in an .xlsx as well as a .csv. Genuinely numeric columns are still treated as numbers.
Are my formulas kept?
No. The loader reads saved formula results rather than recalculating formulas. Cached results may be stale or missing, and formulas are not preserved in the cleaned workbook. Recalculate and save the original in Excel before uploading, and keep that original if you need the formulas.
Is my cell formatting preserved?
No. Fonts, colours, fills and column widths are not carried across — what comes back is the data, not a styled copy of the workbook.
What happens if my workbook has more than one sheet?
Only the first sheet is read, and only that sheet is in the file you download — the others are not included. If your workbook keeps lookups or notes on separate sheets, clean the data sheet on its own and keep the original workbook.
How long is my file kept?
Anonymous uploads and their results are deleted an hour after cleaning. Signed in, results follow your account's retention period, seven days by default, and you can shorten it or delete a result yourself at any time. Read the privacy policy.
Upload a workbook and review what changed.
No signup required.
Clean a file free →Get in touch if you have a question first.