XLS to XLSX
Convert legacy .xls to modern .xlsx.
Click to upload or drag & drop
Select a legacy Excel file (.xls)
How to use the XLS to XLSX
- 1Upload your legacy Excel file (.xls)
Drag and drop or click to select the legacy Excel file (.xls).
- 2Convert to XLSX
Click Convert to XLSX and we process it on our secure server.
- 3Download
Your XLSX downloads automatically.
Convert XLS to XLSX
This tool converts a legacy Excel .xls spreadsheet into the modern .xlsx format using LibreOffice, so old workbooks open cleanly in current Excel, Google Sheets and other apps.
When to use it
- Modernise an old .xls file for current Excel.
- Import an old spreadsheet into an app that needs .xlsx.
- Clear legacy-format compatibility warnings.
Private & secure
Your file is uploaded over an encrypted HTTPS connection, converted on our server and streamed straight back to your device. Each request runs in its own isolated workspace that is deleted the instant the result is returned, so nothing is ever stored or shared.
Frequently Asked Questions
Are my formulas and formatting kept?
Yes. Cell values, formulas, sheets and formatting are preserved as the file converts to the modern .xlsx format.
Are my files uploaded to a server?
Yes. Unlike our browser-based tools, the XLS to XLSX runs on our secure server because it needs professional desktop-grade software to do the job well. Your file is processed in an isolated workspace and deleted automatically the moment the result is sent back — nothing is stored, logged or shared.
Is it free? Is there a watermark or size limit?
It is completely free with no sign-up and no watermark. Files up to 100 MB are supported per conversion.
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