Convert XLS files to XLSX online, free and without signup. Upload your XLS file below and download the converted XLSX in seconds. You get 10 free conversions every day, and files are automatically deleted after 24 hours.
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XLS is Excel's legacy binary format used before 2007.
XLSX is Excel's modern spreadsheet format based on XML.
Upload your XLS file using the button above. Files up to your plan limit are supported.
Click Convert. Your file is processed on our servers with industry-standard engines like FFmpeg and LibreOffice.
Download your XLSX file. It stays available for 24 hours, then it is deleted automatically.
Yes. ConvertFly offers 10 free conversions every day with no signup required. For higher volumes, credit packages start at $8.
Yes. Files are encrypted during transfer and automatically deleted after 24 hours. ConvertFly is operated by Dizzus GmbH in Switzerland.
No. The conversion runs entirely in the cloud: it works from any browser, on desktop or mobile.
| XLS | XLSX | |
|---|---|---|
| Type | spreadsheet | spreadsheet |
| In short | XLS is Excel's legacy binary format used before 2007. | XLSX is Excel's modern spreadsheet format based on XML. |
Convert XLS to XLSX online for free. Fast, secure spreadsheet conversion powered by industry-standard engines. No signup required, files auto-delete after 24 hours. Operated by Dizzus GmbH on private infrastructure.