OpenNestXLSX to CSV Converter
Convert Excel Workbook to CSV directly in your browser. Your files never leave your device — no uploads, no account, no tracking.
Choose files
or drag & drop here
100% local — your file never leaves this device.
How to convert XLSX to CSV
Choose your XLSX file
Select a Excel Workbook from your device — click or drag & drop.
Pick CSV as the output
We auto-detect your file and show CSV as a recommended target.
Convert & download
Everything runs locally in your browser, then you download the result instantly.
Why use OpenNest to convert XLSX to CSV?
100% local
Your XLSX file is converted entirely in your browser — nothing is uploaded.
Free & no account
No signup, no limits. Convert as many files as you need, on any device.
Private by design
No servers, no tracking, no logs. Close the tab and every trace is gone.
Supported input & output
| Input — Excel Workbook | .xlsx, .xls · application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |
|---|---|
| Output — CSV | .csv · text/csv |
FAQ — XLSX to CSV
Is XLSX to CSV conversion free?
Yes — completely free, no account, no signup, and no file limits.
Do I need to upload my XLSX file?
No. The conversion runs entirely in your browser; your file never leaves your device.
How do I convert XLSX to CSV?
Select your XLSX file, choose CSV as the target, and click Convert. The result downloads instantly.
Is the output quality preserved?
Conversion is done locally with high-quality output, preserved to the extent the target format allows.