How do I convert XLSX to XLS online for free?

Document Conversion

Convert XLSX to XLS Online

Free online Excel (OOXML) to Excel Spreadsheet converter. Files are processed locally in your browser — no uploads, 100% private.

.XLSX

.XLS

Drop your .XLSX file here

or click to browse from your device

Accepts .XLSX files

100% Private

Files never leave your device

Instant

In-browser processing

No Account

No sign-up required

How to Convert XLSX to XLS Online

1Upload your .XLSX file using the drop zone above or click to browse
2Your file converts automatically to .XLS format entirely within your browser
3Download your converted file — no account or email needed

Frequently Asked Questions

Upload your Excel (OOXML) file using the drop zone above. Your file is instantly converted to Excel Spreadsheet format right inside your browser using client-side processing — no account, no software, and no cost. When conversion is complete, click Download to save your XLS file.

Completely. Our converter runs 100% in your browser using local processing, so your XLSX file never leaves your device or touches any external server. We do not store, access, or transmit your files at any point.

Desktop: up to 500 MB. Mobile: up to 200 MB. All processing happens locally in your browser — your files are never uploaded to any server.