XLS to XLSX Converter
Convert your XLS files online for free. The Toolisoft XLS to XLSX Converter allows you to quickly upload, convert, and download files directly in your browser without installing software.
Select your file here to get started
or drop your XLS files here.
What Is a XLS to XLSX Converter?
A XLS to XLSX Converter is an online formatting utility used to shift digital file architectures from the XLS format to the XLSX format. Since XLSX supports features such as supports formulas, formatting, charting engines, cell styles, macros, and multiple tab sheets., designers, engineers, and content editors convert files to XLSX to preserve data structures, while XLS is optimized for bookkeeping systems, accounting logs, mathematical charts, and database listings..
Our browser-based conversion service helps you quickly transition files without downloading heavy desktop packages. Your data security remains intact since all conversion scripts execute client-side.
How to Convert XLS to XLSX
- Select and upload your XLS files into the file dropzone above.
- The system dynamically verifies that XLSX is set as your output format.
- Click the "Convert" button to launch the conversion processor.
- Download your newly converted files individually or packed together inside a ZIP archive.
XLS vs XLSX Comparison
| Feature / Property | XLS | XLSX |
|---|---|---|
| File Extension | .xls |
.xlsx |
| Category | Spreadsheet | Spreadsheet |
| Compression Type | Lossless Compression | Zip-compressed XML structure |
| Transparency Support | No | No |
| Relative File Size | Medium | Medium |
| Compatibility | High | High (Microsoft Excel, Google Sheets, LibreOffice Calc) |
| Advantages | Calculates cells dynamically and displays matrices with clean columns. | Supports formulas, formatting, charting engines, cell styles, macros, and multiple tab sheets. |
| Disadvantages | Requires appropriate viewing application software to read. | Complex sheets may load slowly or break when imported into non-Microsoft spreadsheet tools. |