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Upload the legacy workbook, convert, download the XLSX.
Select your .xls file — or drag it into the tool.
Start the conversion in your browser.
Download the upgraded .xlsx.
Open it in Excel or any modern spreadsheet app.
Built for speed, privacy and reliability — on any device.
XLSX’s ZIP+XML structure weighs less and resists corruption better than legacy XLS.
Excel, Google Sheets, Numbers, LibreOffice and every API prefer XLSX.
Processed in your browser and removed right after.
No account, no watermark, no limits.
Supports DOCX, XLSX, PPTX and legacy formats. Formatting and layout are retained as closely as possible.
Add the .xls to the tool above and start the conversion — the .xlsx downloads in seconds, free, no account.
XLS is Excel’s binary format from 1997–2003. XLSX (2007+) is a ZIP of XML — more compact, more resilient, and the format modern tools and APIs expect.
Sheets, values, standard formulas and formatting convert cleanly. Ancient macro sheets or exotic chart types may simplify — check the result.
The file is processed in your browser and automatically deleted right after — usually within minutes, never shared, never stored.
Legacy export systems are everywhere — converting to XLSX makes those files usable in modern tools, dashboards and import pipelines.
Yes — completely free, no account, no watermark, no daily limits.
Convert XLS files to XLSX online