Excel Converter (XLSX to XLS)

Convert .xlsx files to .xls format locally.

The simplest, safest way to convert modern Excel files to legacy formats. Do you have older software that only accepts the classic .xls format? Excel Converter Pro is a lightweight tool designed to bridge the gap between modern spreadsheets and legacy systems. Key Features: Privacy First: Unlike online converters, your files are NEVER uploaded to a server. All conversion happens locally in your browser. Drag & Drop: Simply drag your .xlsx file into the window and click convert. High Fidelity: Powered by the industry-standard SheetJS engine for reliable data preservation. No Size Limits: Process large workbooks without waiting for uploads or downloads from a remote server. How to use: Pin the extension to your toolbar. Click the icon to open the converter window. Drag and drop your .xlsx file. Click "Convert to .XLS" and choose where to save your new file. Permissions Explained: Downloads: Needed solely to save the converted file to your computer. No Identity/Data Access: We don't see your spreadsheets, your emails, or your browsing history.