XLS to XLSX
Convert old binary Excel XLS files to the modern XLSX format. XLSX has been the default Excel format since Office 2007 — it is smaller, more reliable, and better supported across all platforms. In-browser conversion with SheetJS. No signup required.
Updated June 2026
- 1Upload your XLS file
- 2Conversion runs instantly
- 3Download your XLSX file
Drop your XLS file anywhere, click to browse
Excel 97-2003 · Converted XLSX downloads automatically
How to Use XLS to XLSX
- 1
Upload your XLS file
Drag and drop your XLS file into the upload area, or click to browse and select it from your device. Nothing is sent to a server.
- 2
Conversion runs instantly
ToolBubble converts the file to XLSX directly in your browser — no waiting in an upload queue.
- 3
Download your XLSX file
Once processing finishes, the converted XLSX file downloads automatically to your device.
Frequently Asked Questions
What is the difference between XLS and XLSX?▼
Is formatting preserved in the conversion?▼
Why should I convert XLS to XLSX?▼
Is the conversion done in the browser?▼
What happens to Excel macros?▼
How to use XLS to XLSX
- 1
Upload your XLS file
Drag and drop your XLS file into the upload area, or click to browse and select it from your device. Nothing is sent to a server.
- 2
Conversion runs instantly
ToolBubble converts the file to XLSX directly in your browser — no waiting in an upload queue.
- 3
Download your XLSX file
Once processing finishes, the converted XLSX file downloads automatically to your device.
Frequently asked questions
Everything you need to know about xls to xlsx.
Explore more category tools
Convert, optimize and organize your files with our full collection of free tools.