XLS to XLSX
Convert XLS files to XLSX format quickly with our free online tool. No software installation required - upload your file and download the result in seconds. Browse more Spreadsheet Tools.
Drop your file here or click to browse
Supports XLS files up to 100 MB
Conversion complete
Continue to...
How it works
Select or drag your XLS file into the converter.
Click convert and wait for processing to finish.
Save your XLSX file instantly.
Supported formats
Our XLS to XLSX converter maintains quality while ensuring compatibility across devices and applications.
Frequently asked questions
Yes, Convert Online provides free access to the XLS to XLSX converter. There are no hidden fees for standard conversions.
You can upload files up to 100 MB per conversion. For larger files, consider compressing them first or splitting into smaller parts.
Your files are processed securely and are not permanently stored. We prioritize your privacy and delete temporary data after conversion.
Our tool supports standard XLS file formats. If your file does not upload, ensure it is not corrupted and matches the expected format.
Absolutely. Convert Online is fully responsive and works on smartphones, tablets, and desktop computers.