CSV to Excel online: free, private, no upload
Convert CSV files to XLSX.
How it works
- 1
Drop one or more CSV files.
- 2
Convert them.
- 3
Download the XLSX files.
Turn CSV or TSV files into Excel workbooks. The delimiter is detected automatically, numbers stay numbers and Unicode text is preserved. Runs in your browser.
Turn CSV or TSV files into Excel workbooks. The delimiter is detected automatically, numbers stay numbers and Unicode text is preserved. Runs in your browser. Spreadsheets are read and converted locally in your browser, so sensitive data never leaves your device. Only the first sheet of data is created; styling is not added.
What people use it for
- CSV to Excel for exports, reports and data clean-up.
- Move data between spreadsheets, apps and APIs.
- Process financial or customer data privately.
Tips for best results
- Only the first sheet of data is created; styling is not added.
- Remove empty rows and merged cells first for the cleanest output.
- Large workbooks may take a moment to process.
Your files never leave your device
Unlike most online PDF tools, Intelli File does not upload your documents to a server. Everything runs in your browser using your own device, so contracts, IDs and financial records stay private. Only a small usage counter is sent so we can apply daily limits.
Read how we handle privacyWhat to do next
After this, you may want to Excel to CSV, Excel to JSON, or Merge Excel.
Frequently asked questions
Is the delimiter detected?+
Yes. Commas, semicolons and tabs are detected automatically.
Are my files uploaded anywhere?+
No. The conversion runs inside your browser, so your file never leaves your device.
Is it free?+
Free accounts get a few tasks per day; sign up for more, or go Pro for unlimited use and larger files.
Is there a file size limit?+
Files are processed on your device, so the practical limit is your browser's memory. Only the first sheet of data is created; styling is not added.
Does it work on my phone?+
Yes. Modern mobile browsers run this tool, although large files are faster on a computer.