Data
Turn your CSV files into XLSX in seconds. Everything happens in your browser: nothing is uploaded to any server.
Drag your files here
Or paste them with Ctrl+V. They never leave your device.
Opening a CSV in Excel sometimes breaks accents or puts everything in one column. Converting to XLSX here lets you choose the separator and encoding, so the workbook comes out right.
It has a single sheet, no formatting or formulas, and accented characters sometimes break. As XLSX you open it in Excel with its columns and sheets.
CSV stores a table as text: one row per line with columns separated by commas (or semicolons in some locales).
Strengths: Every spreadsheet, database and app can import it.
Limits: It has a single sheet, no formatting or formulas, and accented characters sometimes break.
XLSX is the Microsoft Excel format: a workbook with one or more sheets, data types and formatting.
Strengths: It is what almost any office expects.
Limits: Other apps and databases usually ask for CSV to import data.
No. The CSV to XLSX conversion runs entirely in your browser, with code downloaded from this site and executed on your device. You can check it in the Network tab of the developer tools or by going offline after the page loads.
Open the options and pick the “Windows (Western European)” encoding, which older Excel versions use for CSV. UTF-8 files are detected automatically.
Up to 1 GB on desktop and about 200 MB on mobile, although a huge spreadsheet may take a few seconds.
Yes. Drop as many CSV files as you like: several are converted at the same time, depending on your processor cores, and when they finish you can download each XLSX or all of them in a ZIP.