Convert XLSX to CSV
Turn one sheet of an Excel file into a CSV file. The file is read in your browser and never uploaded.
Drag an Excel file hereChoose XLSX file
One .xlsx file up to 50 MB. The older .xls format is not supported. Nothing is calculated or run.
Processed on your device, no upload
Guide and details
How it works
- Choose an XLSX file or drop it onto the area above.
- Pick the sheet and check the preview.
- If needed, open the advanced settings for delimiter, line endings, date format and empty rows.
- Choose “Create CSV” and download the file.
How Excel becomes a CSV file
CSV is a plain text file in which every line is a table row. The tool reads the cell values of the chosen sheet and writes them with correct quoting: fields containing the delimiter, quotation marks or line breaks are put in quotes. The output is UTF-8, optionally with a BOM so that older Excel versions show umlauts correctly. You choose comma, semicolon or tab.
Numbers are not converted through floating point. Long numbers, leading zeros and decimal places stay as they are in the file. Date values are recognised from the cell format and written as ISO text (2024-03-05), or as the stored number if you prefer.
Formulas, macros and limits
Formulas are never calculated. The tool uses the result that Excel stored in the file instead. If no stored result exists, the cell stays empty and the page tells you. Macros are ignored and never run, links to other files are not loaded.
The XLSX file is read carefully like any foreign file: sizes are counted while unpacking, and XML with a DOCTYPE or entities is refused. Files up to 50 MB and up to 3,000,000 cells per sheet are supported, less on smartphones. The old XLS format, XLSB and password protected files are not opened. Formatting, colours, charts and images are naturally lost in CSV, as are other sheets that you do not select.
Frequently asked questions
Is my Excel file uploaded?
No. The file is read and converted only in your browser.
What happens to formulas?
They are not calculated. The result stored in the file is used. If it is missing, the cell stays empty and you get a note.
Are several sheets converted?
A CSV file always holds exactly one sheet. Choose the one you want and convert the others one after another.
Why does Excel show my umlauts wrongly?
Turn on the UTF-8 mark (BOM) in the advanced settings. Excel then recognises the character encoding.
Are long numbers or leading zeros falsified?
No. Numbers are taken from the file as text. When you open the CSV in Excel, Excel may reformat them itself, which is out of our hands.