Convert CSV to XLSX

A CSV is text; a spreadsheet is not. This writes a real .xlsx with typed cells, so numbers arrive as numbers and Excel stops mangling anything that looks like a date. Sidesteps the import dialog entirely.

Drop CSV file(s) to start

or click to browse

What is CSV?

The least glamorous and most durable data format there is: rows of values separated by commas, readable by every spreadsheet and database ever written. All its subtlety is in quoting - a value with a comma in it has to be wrapped in quotes, and a quote inside that has to be doubled.

What is XLSX?

A modern Excel workbook, which is really a zip full of XML. Unlike a CSV it knows what a number is, holds multiple sheets, and keeps formulas and formatting. It's what people mean when they say 'send me a spreadsheet'.

Your files never leave your device · no magic required