Spreadsheet Conversion
Convert XLS to XLSX Online — Free
Fast, free XLS to XLSX converter. No registration required.
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How to Convert
1
Upload your .xls file by dragging it into the upload area or clicking to browse.
2
Choose your output settings. The default settings work great for most files.
3
Click Convert and download your .xlsx file when it's ready.
What is XLS?
XLS is the legacy Microsoft Excel format used before Office 2007. While superseded by XLSX, it's still widely found in enterprise data exports and archived files.
Format Details
- Full Name
- Microsoft Excel 97-2003
- Extension
- .xls
Key Features
- Legacy support
- Wide compatibility
- Spreadsheet
- Data analysis
What is XLSX?
XLSX is the modern Microsoft Excel format. It's the standard for spreadsheets containing data, formulas, charts, and pivot tables.
Format Details
- Full Name
- Microsoft Excel Spreadsheet
- Extension
- .xlsx
Key Features
- Spreadsheet
- Formulas
- Charts
- Data analysis
XLS vs XLSX
| Feature | XLS | XLSX |
|---|---|---|
| Full Name | Microsoft Excel 97-2003 | Microsoft Excel Spreadsheet |
| Extension | .xls | .xlsx |
| Best For | Legacy support | Spreadsheet |
Frequently Asked Questions
Yes. You can convert up to 5 files per day completely free, with no watermark or registration required.
Most files convert in under 30 seconds. Larger files (over 500MB) may take 1-3 minutes.
No. Our converter uses optimized encoding settings by default to preserve the original quality.
Free users can convert files up to 100MB. Pro users can convert files up to 2GB.
Yes. Our converter works in any modern web browser on any device.