XLS to XLSX Converter
Convert legacy Excel 97-2003 (.xls) files to modern Excel (.xlsx) format. Free, instant, and private.
Drop your files here or click to upload
Supports .xls · up to 50MB · or paste a file from your clipboard
Use this free tool to convert XLS to XLSX online - upgrade legacy Excel 97-2003 workbooks to the modern .xlsx format in seconds, right in your browser.
How to Convert XLS to XLSX
- Upload your XLS file - Drag and drop or click to browse for your .xls file.
- Wait for conversion - Our tool processes your file instantly in your browser.
- Download - Click the download button to save your converted XLSX file.
Why Convert XLS to XLSX?
The XLS format was used by Microsoft Excel from 1997 to 2003. While it still works, the modern XLSX format offers several advantages:
- Smaller file size - XLSX uses ZIP compression for smaller files
- Better compatibility - Modern apps and services prefer XLSX
- More features - XLSX supports more rows, columns, and features
- Open standard - XLSX is based on Open XML, an open standard
- Security - XLSX has better security features
Features
- Instant conversion in your browser
- Preserves all data, formulas, and basic formatting
- Supports multi-sheet workbooks
- 100% private - files never leave your device
- No file size limits for reasonable files
- No signup or registration required
What's next?
Keep going with one of these tools.