Use this XLS to XLSX Spreadsheet converter tool to quickly convert your XLS files to XLSX in bulk.
How to use the XLS to XLSX File Converter Tool
The XLS to XLSX file converter is free, simple, fast, privacy-focused, requires no email address to use, and does not use watermarks. Convert your files in bulk while never having to worry about your privacy. Your files are converted in the web browser without our server ever knowing about them, making ConvertSimple.com's file converter the most privacy-concious tool on the web.
- Upload your XLS files by dragging and dropping them into the box at the top, or by clicking
Select Files to Convert. - You can change what type of file you want to convert your XLS files to by changing the Convert to option near the top of the page.
- Click the Convert button to begin the bulk XLS to XLSX conversion.
- The files will be converted. You can download the converted files individually or click Download All to download a ZIP file with all of your converted XLSX files.
- Your files are secure. ConvertSimple's file converter does not send your files to our servers for conversion, the process is done completely in your web browser. That's what makes ConvertSimple's file converter the safest and fastest file converter out there.
Conversion library used: ImageMagick
XLS Format
| Name | XLS |
| Full form name | Microsoft Excel Spreadsheet |
| File extension | .xls |
| Type of format | Spreadsheet |
| MIME type | application/vnd.ms-excel |
XLSX Format
| Name | XLSX |
| Full form name | Microsoft Excel Open XML Spreadsheet |
| File extension | .xlsx |
| Type of format | Spreadsheet |
| MIME type | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet |