Convert CSV to Excel (XLSX)

Paste CSV data, or drop a .csv file, and download it as a genuine .xlsx workbook, opens directly in Excel or Sheets. Nothing is sent anywhere.

Drop your CSV file here

Choose file

Up to 20MB per file. Stays on this device.

Nothing is sent anywhere. Turn off your Wi-Fi and this page still works - try it.

Or paste CSV

How it works

Drop or choose a .csv file, or paste CSV text directly into the text box.
Review the preview - every row and column carries over, with numeric columns detected automatically.
Download the result as a genuine .xlsx workbook, ready to open in Excel or Sheets.

Example output

Input

sku,name,price
A100,Widget,9.5
A101,Gadget,14
A102,Gizmo,21.75

Output

sku	name	price (number)
A100	Widget	9.5
A101	Gadget	14
A102	Gizmo	21.75

A 3-row CSV becomes a 3-row grid. The price column is detected as numeric and will be a real Excel number, right-aligned here to match.

Frequently asked questions

Is my CSV sent anywhere?

No. Pasted CSV and uploaded files are both read and converted entirely on your device - nothing is sent to a server. Turn off your Wi-Fi after the page loads and it still works. This page loads 10KB of JavaScript, gzipped - about what your browser's network tab will show for this page's own scripts.

Which columns become real Excel numbers?

Only a column where every value looks like a plain integer or decimal - a single non-numeric-looking value anywhere in the column keeps the entire column as text, since guessing at a real type risks silently corrupting a value that only looks numeric, like a leading-zero code (0042 becoming 42).

Is this different from just renaming a .csv file to .xlsx?

Yes - a renamed .csv is still plain text and most spreadsheet programs will refuse to open it, or open it incorrectly. This tool builds a genuine binary .xlsx workbook (the real Office Open XML format) that opens correctly in Excel, Google Sheets, or LibreOffice.

Does the output have a header row?

Yes - the CSV’s own first row becomes the workbook’s first row, unstyled, exactly as it appeared in the source. This tool doesn’t add bold formatting or freeze panes.

Is there a limit on file size?

Uploads are capped at 20MB. Since everything runs in your browser rather than on a server, a very large CSV is more likely to be limited by your device’s own memory than by that cap.

Files are processed locally in your browser and never uploaded. Read more on the privacy page.

Convert CSV to Excel (XLSX)