Excel to CSV
Drop an .xlsx workbook and get clean CSV back. Every sheet is read, dates come out as YYYY-MM-DD instead of raw serial numbers like 45291, and formula cells export their computed value. Nothing is uploaded — the workbook is unzipped and parsed inside your browser.
How to convert Excel to CSV
- Drop an
.xlsx(or.xlsm) workbook onto the box above. - Pick the sheet you want from the dropdown — the row count next to each name tells you which one holds the data.
- Choose a delimiter if you need semicolons or tabs instead of commas.
- Download .csv for the current sheet, or All sheets .zip to get every sheet as its own file.
What happens to dates, formulas, and blanks
- Dates — Excel stores them as numbers. Cells with a date format are converted to
YYYY-MM-DD(orYYYY-MM-DD HH:MM:SSwhen the format includes a time). The 1904 date system used by some old Mac files is honoured. - Formulas — the cached result is exported, not the formula text. That's what a CSV can hold.
- Merged and blank cells — exported as empty fields, keeping row and column positions intact so the grid still lines up.
- Trailing junk — Excel often reports a sheet as thousands of rows tall. The trim option drops fully empty trailing rows and columns.
FAQ
Can it open an old .xls file?
No — .xls is a different, binary format. Open it in Excel or LibreOffice and re-save as .xlsx first; the tool tells you when it spots one.
Is the workbook uploaded to a server?
No. The .xlsx is a ZIP file, and it's unzipped and parsed locally in your browser. Nothing is transmitted.
My numbers come out with long decimals — why?
Excel shows a rounded display value but stores full precision. CSV export uses the stored number. Round the column in Excel first if you need the displayed value.
How do I get CSV back into Excel cleanly?
Use CSV to Excel for a real .xlsx, or add a UTF-8 BOM with Encoding & BOM so Excel reads accented characters correctly.
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