CSV
Comma-separated values
CSV is plain text with one table row per line. Every spreadsheet, database and programming language reads it, but it has no formatting, formulas or multiple sheets.
Extensions: .csv
CSV to XLSX converter
Convert CSV files to XLSX on Windows 10 and 11: free, offline and in batches. Drag the files onto XLSX in Filee's format donut and the XLSX files appear next to the originals.
How to convert CSV to XLSX on Windows
- 1
Select your CSV files
In File Explorer or on the desktop, select one CSV file or as many as you like.
- 2
Hold Ctrl and drag
Hold Ctrl (or the key you set in Filee) and drag the files. A donut of formats opens at the cursor. Prefer menus? Right-click and choose Convert with Filee.
- 3
Drop on XLSX
Release the files over XLSX. A progress ring counts up, and each XLSX file is saved next to its original.
What Filee does for CSV → XLSX
An XLSX workbook can hold the formatting, formulas and extra sheets that CSV can't. Select all your CSV exports and drop them at once to get one workbook per file, without Excel's import dialog.
- Built in: works right after installing Filee, with nothing else to download.
- No Microsoft Office or LibreOffice needed.
- Batch: one file or hundreds, converted in parallel; a failure never stops the rest.
- Private: files are converted on your PC and never uploaded, even without internet.
- Saved next to the original, or in a folder and with a file name pattern you choose.
CSV can also become
- ODS
- HWPX
- HTML
About CSV and XLSX
XLSX
Excel workbook
XLSX is the Microsoft Excel workbook format since Excel 2007. One workbook can hold several sheets with formulas, formatting, charts and pictures.
Extensions: .xlsx
Convert CSV to XLSX for free
Filee is a free, open-source file converter for Windows 10 and 11. It works offline and converts 180+ formats with one drag and drop.
Download for Windows