Convert CSV to Excel (XLSX)
Opening a CSV directly in Excel often strips leading zeros from ZIP codes, turns long IDs into 1.23E+15, or garbles non-English text. This tool builds a real .xlsx file and decides cell by cell which values are safe to store as numbers.
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How to use
- Choose a CSV, TSV or TXT file (up to 50 MB) or paste the data.
- Check the auto-detected delimiter and encoding; override them if the preview looks wrong.
- Decide whether to convert numbers and, optionally, rename the sheet.
- Download the .xlsx file.
Features and limits
- The delimiter is detected automatically, or you can set it yourself.
- UTF-8 is detected automatically; other files are read as Windows-1252 (older Western Excel). EUC-KR, Shift_JIS and GB18030 can be chosen manually.
- With "convert numbers" on, numeric text becomes number cells, except values with leading zeros (00123, ZIP codes, phone numbers) and integers longer than 15 digits, which stay text.
- The result is a single-sheet workbook with an editable sheet name.
- Excel's limit of 1,048,576 rows per sheet applies.
FAQ
How do I keep leading zeros when opening a CSV in Excel?
Excel drops leading zeros because it converts anything that looks numeric into a number. Converting the CSV here stores values like 00123 as text cells, so the zeros are still there when you open the .xlsx.
Why do long numbers turn into 1.23E+15 or end in zeros?
Excel stores only 15 significant digits, so longer numbers such as card or account IDs lose their last digits. This tool keeps integers longer than 15 digits as text to preserve them exactly.
Can I convert TSV or tab-delimited text files?
Yes. Tabs are detected like any other delimiter, and you can also select tab manually.
Can I merge several CSV files into one workbook?
Not currently. Each conversion produces one .xlsx file with one sheet.