Turn CSV or TSV files into a real .xlsx workbook with numbers as numbers, readable column widths and filter buttons. Combine several CSVs into one workbook, a sheet per file.
Works in your browser. What you paste or upload is processed on your device.
Choose one CSV or TSV file, or several to combine. They are read in your browser.
Confirm the columns are split correctly. If not, pick the delimiter or encoding yourself.
Keep numbers as numbers, add filter buttons and, for several files, choose one workbook or one per file.
Press Convert to Excel and download the .xlsx, or a ZIP when you made several workbooks.
Opening a CSV directly in Excel often goes wrong: everything lands in column A, accents turn into symbols like é, ZIP codes lose their leading zero and long IDs become 1.23E+15. This converter reads the CSV itself and writes a proper .xlsx workbook, so the result opens the same way in Excel, Numbers, Google Sheets and LibreOffice.
It detects the delimiter (comma, semicolon, tab or pipe) and the text encoding (UTF-8, UTF-16 from Excel's "Unicode text", or Windows-1252 from older exports), and shows a preview so you can confirm the columns line up before converting. Plain numbers become real numbers you can sum and sort, while values with leading zeros, phone numbers starting with + and IDs longer than 15 digits stay as text. Columns get widths that fit their content and the header row gets filter buttons. Add up to 20 CSV files to get one workbook with a sheet per file, or one workbook per file.
Limits: dates stay as the text in the CSV rather than being converted to Excel dates, because 03/04/2026 means different days in different countries. The header row is not bolded and panes are not frozen. Excel's own limits apply: 1,048,576 rows and 16,384 columns per sheet.
A CSV that opens badly costs more time than the conversion: re-importing through Excel's wizard, fixing lost zeros by hand, or sending a client a sheet full of garbled names. Converting to .xlsx first gives you a file that opens correctly on any device with one double-click, and doing it in the browser keeps customer and finance data off third-party servers.
Something else? Ask the team
Excel splits a CSV using your computer's list separator. If the file uses commas and your Excel expects semicolons (or the other way round), everything stays in column A. This converter detects the delimiter from the file itself, so the .xlsx always has the right columns.
Yes. Values such as 007 or 01234, phone numbers starting with + and IDs longer than 15 digits are written as text, exactly as in the CSV. Only plain numbers like 42 or -3.5 become numeric cells. You can also turn number conversion off to keep every cell as text.
Yes. Add up to 20 files and choose One workbook: each CSV becomes a sheet named after its file. Choose One workbook per file to get separate .xlsx files in a ZIP instead.
No. The CSV is parsed and the workbook is built in your browser. Our server only records that a run was used; it never receives the file or its contents.
No. Dates are kept as the text in the CSV, because a date like 03/04/2026 is 3 April in India and the UK but 4 March in the US, and guessing wrong silently corrupts data. In Excel you can convert a column with Data › Text to Columns › Date.
Yes, in Safari on iPhone and Chrome on Android. Pick the CSV from Files or Downloads, convert, and open the .xlsx in Excel, Numbers or Google Sheets.
You get one free run of this tool per day, with no account. After that, each run costs 5 credits from a free AI Rank Lab account (1 credit = 1 US cent). One run is one press of the convert button.
Each one opens on its own page and works straight away, with no sign-up.
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