Free tool — no signup
Convert CSV to Excel
Upload a CSV file and get back a single-sheet XLSX workbook.
Your file is never uploaded — no account, no server round trip.
How it works
- 1.Choose a .csv file.
- 2.FillOnce parses it in your browser and builds an XLSX workbook.
- 3.Download the XLSX — nothing was ever uploaded.
Frequently asked questions
Does this upload my CSV anywhere?
No. The CSV file is read and converted entirely in your browser. Nothing is sent to a server.
What will the resulting XLSX look like?
A single worksheet with one row per CSV line — quoted fields and embedded commas are handled correctly.
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