Convert CSV to Excel (XLSX) Online — Free
Runs 100% in your browser — your files never leave your device.
Double-clicking a CSV opens it in Excel — until a comma in a field shreds the columns. This converter builds a real .xlsx workbook from your CSV: RFC 4180 quoting, UTF-8 text, and empty cells all carry over exactly. Drop the file, download the workbook, open it anywhere spreadsheets live. Your data never leaves your device.
How it works
- 1
Drop your CSV file
Any RFC 4180 CSV works — quoted fields, embedded commas, UTF-8.
- 2
Convert
The workbook is built locally in your browser within a second.
- 3
Download the XLSX
One click saves the workbook, ready for Excel, Numbers, or Google Sheets.
About this tool
A real workbook, not a renamed CSV
The tool builds a genuine .xlsx workbook — a real spreadsheet package with proper cells, types, and formatting — rather than a CSV file with an Excel extension. It opens in Excel with columns intact and no import wizard.
Why the difference matters
Excel opening a raw CSV guesses at delimiters and turns identifiers into dates; a real .xlsx carries typed cells and avoids the import step entirely. For reports and data handoffs, the real workbook is what recipients expect.
Types carried over
The conversion writes cell values with their types preserved — numbers stay numeric, so sorting and formulas work immediately after opening. The data comes from your CSV parsed per the standard, with quoting and escapes handled.
Frequently asked questions
Does the .xlsx open in older Excel versions?
Yes — .xlsx is the standard modern spreadsheet format, supported by Excel 2007 onward plus Google Sheets, Numbers, and every major spreadsheet app.
Why not just rename my CSV to .xlsx?
A renamed CSV is still a text file — Excel rejects or mishandles it. The real workbook has the internal structure Excel actually reads.
Is my data uploaded anywhere?
No — the workbook is built entirely in your browser. Exports with customer or financial data never leave your device.