Convert XLS to XLSX
Convert XLS to XLSX online, free — no installation, no sign-up.
or drop files here to convert XLS → XLSX
Max file size 1 GB. Browser-side conversions have no upload limit.
How to convert XLS to XLSX
Add your file
Drop your XLS file above or click Choose Files.
Convert
We convert your file securely on our server over an encrypted connection.
Download
Grab your new XLSX file — done.
What is XLS?
XLS is the legacy binary Microsoft Excel format, standard before Excel 2007.
What is XLSX?
XLSX is the modern Microsoft Excel spreadsheet format.
Frequently asked questions
Drop your XLS file into the box above (or click Choose Files), then click Convert and download your new XLSX file. No account or software needed.
Yes — this converter is completely free with no watermarks and no sign-up.
Yes. Files are sent over an encrypted (HTTPS) connection and automatically deleted from our servers within an hour.
You control the output. Use the advanced options (the gear icon) to set quality, and we preserve as much fidelity as the XLSX format allows.