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XLS to XLSX

Convert old binary Excel XLS files to the modern XLSX format. XLSX has been the default Excel format since Office 2007 — it is smaller, more reliable, and better supported across all platforms. In-browser conversion with SheetJS. No signup required.

Drop your XLS file anywhere, click to browse

Excel 97-2003 · Converted XLSX downloads automatically

Ctrl+Vto paste a copied file

Frequently Asked Questions

What is the difference between XLS and XLSX?▼
XLS is the legacy binary Excel format used in Excel 97-2003. XLSX is the modern XML-based format introduced in Excel 2007. XLSX files are typically 30-75% smaller and are better supported in all modern applications.
Is formatting preserved in the conversion?▼
Basic formatting (bold, italic, fonts, column widths, cell colors, borders) is preserved. Complex features like VBA macros, pivot tables, and some chart types may not fully transfer.
Why should I convert XLS to XLSX?▼
XLSX is the current standard, opens faster, is smaller, and is supported on macOS, Linux, Google Sheets, and LibreOffice without compatibility warnings.
Is the conversion done in the browser?▼
Yes. SheetJS processes the file locally. Your spreadsheet data is never uploaded to any server.
What happens to Excel macros?▼
VBA macros cannot be stored in standard .xlsx files. For macro-enabled workbooks, save as .xlsm instead.