How to use the CSV to Excel Converter
- 1. Choose CSV filesPick one or more files, or paste CSV text.
- 2. Set optionsHeader row, numbers as numbers and keep leading zeros.
- 3. ConvertDownload an .xlsx with one sheet per CSV.
Why convert instead of opening the CSV?
Opening a CSV directly in Excel guesses the types. PIN codes and phone numbers lose their leading zero ("0110" becomes 110), and long IDs turn into scientific notation. This converter writes a real .xlsx with the SheetJS library, applying three rules:
- Numbers become numbers you can add up.
- Values with a leading zero, and digit strings longer than 15 digits (which Excel would round), stay as text.
- Each sheet gets filter buttons on the header row and columns sized to fit.
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Worked example
Converting the sample enquiry list gives pasted.xlsx with one sheet of 10 data rows and 6 columns. The Fee column becomes numbers (25000, 30000 …) that SUM works on, while a phone number like 09876543210 would keep its leading zero as text. Choose three monthly CSVs at once and you get converted.xlsx with three sheets named after the files.
Limits
- Cell colours, bold headers, frozen panes and charts aren't added; the free SheetJS edition doesn't write them. Freeze the header yourself with View → Freeze Panes → Freeze Top Row.
- Dates stay as text unless they're already numbers; use our data cleaning tool to standardise them first.
- Sheet names are cut to Excel's 31-character limit, and characters Excel doesn't allow in sheet names (such as / and :) are replaced.
- Each worksheet holds up to 10,48,576 rows, Excel's own limit.
Tip for big exports
If you only need to read a large CSV, opening it in Excel is fine. Convert it when you will share the file, add formulas or keep leading zeros safe, because every save of a plain CSV can lose those details again.
Frequently asked questions
Will Excel complain about the file?
No. It's a standard .xlsx that Excel, Google Sheets and LibreOffice open normally.
Can I convert semicolon CSVs?
Yes. Commas, semicolons, tabs and pipes are detected automatically.
Is the CSV to Excel converter free?
Yes. You can open the CSV to Excel converter, load files and set every option without signing up. When you convert a file for the first time, we ask once for your name and WhatsApp number; after that it, and every other Uncodemy tool, opens straight away.