Excel to CSV

When you drop a workbook, every sheet is read and listed with its row count. Pick the one you want and the CSV updates immediately, without uploading the file again. The download keeps the workbook's name, so sales.xlsx becomes sales.csv; rename the file when you export several sheets.

The first row of the sheet's used area becomes the CSV header. Blank header cells are named Column1, Column2, and so on by position. Rows where every cell is blank are skipped, which removes the spacer rows that often sit between blocks of data.

A CSV holds the underlying cell values, not Excel's formatting. A cell showing $1,200.00 exports as 1200, 15% exports as 0.15, and a formula exports the result Excel saved the last time the workbook was calculated. If a formula result looks stale, open the workbook, recalculate, and save it before converting.

Dates need particular care. Excel stores a date as a serial number of days since 1900, and that number is what comes out: 2026-01-15 exports as 46037. To keep readable dates, add a helper column in Excel with =TEXT(A2,"yyyy-mm-dd") before converting, or convert the serial numbers in the tool that reads the CSV. Our article on Excel to CSV without data loss walks through this and other traps.

The tool reads .xlsx workbooks (Excel 2007 and later, and exports from Google Sheets, LibreOffice, and Numbers). Older .xls files and password-protected workbooks are not supported; re-save them as .xlsx first.

To keep the browser responsive, files up to 25 MB are accepted, the first 50 sheets are read, and each sheet is capped at 100,000 rows and 500 columns. If a cap is hit, a warning says exactly what was left out. The CSV uses commas, quotes values only where needed, and ends lines with CRLF.