Excel ⇄ CSV
Convert Excel (.xlsx) files to CSV and back, in the browser. Everything runs on your device — nothing is sent to a server.
Drag & drop an .xlsx file, or click to choose
The file is processed in your browser and never uploaded to a server.
Example
Example Input
(upload an .xlsx)
Example Output
id,name 1,Aji 2,Bob
How to Use
- 1Choose a mode: "Excel → CSV" (upload .xlsx) or "CSV → Excel" (paste CSV).
- 2Upload a file or paste your CSV.
- 3Click Convert. For CSV → Excel, click Download to save the .xlsx.
About Excel ⇄ CSV
Excel ⇄ CSV turns an Excel spreadsheet file (.xlsx) into text CSV, and builds an .xlsx file from CSV data — both without opening Microsoft Excel or uploading the file.
The "Excel → CSV" mode reads the first worksheet and outputs CSV. The "CSV → Excel" mode assembles an .xlsx (with a bold header) ready to download.
The whole process runs in your browser using the ExcelJS library — your file never leaves your device. It is ideal for sensitive data.
FAQ
Is my data sent to a server?
No. Excel ⇄ CSV runs entirely in your browser using client-side libraries. Your data never leaves your device.