How to use
- Paste CSV or open a .csv, .tsv or .txt file. The encoding is detected automatically.
- Check the preview. Change the delimiter if the columns look wrong.
- Set a sheet name if you like, then download the .xlsx file.
Options explained
- Delimiter
- Detect works for commas, semicolons, tabs and pipes. Choose one explicitly if a column contains lots of the other characters.
- Store numbers as values
- Numbers with up to 15 digits and TRUE/FALSE become real Excel values you can calculate with. Longer numbers (ID and card numbers) and values with leading zeros stay as text so no digits are lost.
- Encoding
- CSV files saved by Excel on Chinese Windows are usually GBK; they are detected and converted, and the workbook stores everything as Unicode.
How each value is stored
With Store numbers as values on, each cell is judged on its text:
| CSV cell | Stored as |
|---|---|
731, -3.5, 0.25 |
Number |
123456789012345 (15 digits) |
Number |
1234567890123456 (16 digits) |
Text |
00731 |
Text, so the zeros stay |
6222021234567890123 |
Text |
TRUE, FALSE, true, false |
Boolean |
2026-01-05, 1,200, +5, 1e3 |
Text |
Excel keeps only 15 significant digits of a number, which is why anything longer must stay text to avoid changing its last digits. Column widths are set from the first 500 rows, up to 60 characters wide, and the sheet name is cut to 31 characters, the Excel limit.
Frequently asked questions
Why not just open the CSV in Excel?
Excel guesses types as it opens a CSV, so 00731 becomes 731, long numbers lose their last digits, and some values turn into dates. Converting here keeps the text as it is.
Are dates converted to Excel dates?
No. Dates are kept as the text in the CSV so nothing is misread; format the column in Excel if you need date arithmetic.
Is there a row limit?
The xlsx format allows 1,048,576 rows per sheet. Files of tens of thousands of rows convert in a few seconds in the browser.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.