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Office

Free CSV to Excel & Excel to CSV Converter

Upload a CSV or Excel file and convert it the other way, instantly. Nothing leaves your browser.

What this does: converts a CSV file into a real .xlsx workbook, or an Excel file (.xlsx or .xls) into plain CSV, entirely in your browser using the SheetJS library. It detects the direction automatically from your file's extension, previews the first rows, and lets you pick a sheet when a workbook has more than one. No signup, no server upload: your spreadsheet data never leaves your device.

Click to select a file or drag and drop it here.

Accepts .csv, .xlsx, or .xls. The output action appears automatically.

Frequently asked questions

Is this CSV to Excel converter really free, and does it work in my browser?

Yes. It runs entirely client-side using the SheetJS JavaScript library, with no signup, no installation, and no limit on how many times you use it.

Is my spreadsheet or CSV data uploaded to a server?

No. Your file is read and converted locally in your browser's memory. Nothing is transmitted anywhere, which makes this safe for private or sensitive data.

Can I convert a multi-sheet Excel workbook, and are there any size limits?

Yes, but CSV has no concept of multiple sheets, so you convert one sheet at a time using the sheet tabs shown after upload. Very large workbooks with 100,000 or more rows may take a few seconds to process since everything runs on your device.