Convert your .csv files to .xlsx format online for free. No software to install. Fast, secure, and easy.
Free — 3 conversions per day
Drag and drop your .csv file or click to browse.
Select XLSX as your output format.
Click Convert and download your .xlsx file.
Converting CSV to Excel format lets you add formatting, formulas, charts, and multiple sheets to your raw data. This is essential when you need to present data professionally, perform calculations, or share organized reports with colleagues who work in Excel or Google Sheets.
CSV (Comma-Separated Values, introduced in 1972) uses None (plain text) compression. XLSX (Office Open XML Spreadsheet, introduced in 2007) uses ZIP (containing XML parts) compression. CSV browser support: Universal (displayed as plain text). XLSX browser support: None (requires office application or online viewer).
The quality impact depends on the specific settings used during conversion. XLSX uses compression that may affect quality depending on the chosen settings.
Typical CSV file size: 100,000 rows x 10 columns of text: ~5-15 MB. Typical XLSX file size: A 10,000-row spreadsheet with formulas: ~500 KB - 2 MB. Expect a dramatic file size reduction — often 5-20x smaller — when converting from uncompressed CSV to XLSX.
When importing CSV to Excel, check the delimiter detection — some CSV files use semicolons instead of commas, especially in European regions. Also verify that date columns are parsed correctly, as CSV date formats vary widely and Excel may misinterpret them.
Convert CSV to XLSX with 3 free conversions per day. No hidden fees.
Create a free account in 10 seconds and start converting immediately. No credit card required.
Files are encrypted during transfer, processed on secure servers, and deleted immediately after conversion.
Convert files from any device — desktop, tablet, or phone. No software to install, works in any modern browser.
SquishConvert supports over 358 file conversion combinations across images, documents, audio, and video.
Your converted .xlsx file maintains the best possible quality. No unnecessary compression or quality loss.
You get 3 free conversions per day. Upgrade to Pro for unlimited conversions.
Most files convert in under 10 seconds. Larger files may take a bit longer depending on size.
Yes. Files are encrypted during transfer, processed on secure servers, and deleted immediately after conversion. We never store your files.
Currently, SquishConvert converts one file at a time. Batch conversion is coming soon — stay tuned!
Free users can convert files up to 10 MB. Pro users can convert files up to 500 MB.