CSV ⇄ Excel
Convert CSV to Excel (.xlsx), or Excel to CSV. Runs entirely in your browser.
Convert a plain CSV file into a formatted Excel workbook, or pull a single sheet back out of an XLSX file as CSV. Handles the format mismatch that comes up constantly when a client wants the Excel version of a CSV export, or when a script needs plain CSV from a spreadsheet someone emailed you. Conversion runs locally using the SheetJS library, with no file upload and no row limit beyond your browser's memory.
Runs on your device. This tool processes your file inside this browser tab. Nothing is uploaded, so it also works offline once the page has loaded, and closing the tab discards the file from memory.
Loading tool
How it works
- 01
Upload a CSV or XLSX file.
- 02
The tool detects the direction automatically based on file type.
- 03
Download the converted file.
Details
- Category
- Developer & data
- Formats
- CSV
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-12
Common questions
Does it upload my file?
No - conversion happens locally with SheetJS.
Multiple sheets?
Excel to CSV exports the first sheet. CSV to Excel produces a single-sheet workbook.
Are formulas preserved when converting Excel to CSV?
No - CSV is a plain-text format, so only calculated values are exported, not formulas.
Does it handle commas and quotes inside cells?
Yes - values containing commas, quotes, or newlines are properly quoted and escaped in the CSV output.
Use this from your code
This tool is also a REST endpoint, so you can run it in a pipeline instead of by hand. Each call costs 2 credits and needs an API key. See the API reference for every parameter.
curl -X POST https://fileoven.com/api/v1/tools/csv-excel \ -H "Authorization: Bearer sk_live_..." \ -F "file=@input.csv" \ -F "to=xlsx" \ -o converted.xlsx