Convert XLS to XLSX online, for free.
Simply upload your XLS files and click the convert button. You can also batch convert XLS to XLSX format.
We use both open source and custom software to make sure our conversions are of the highest quality. In most cases, you can fine-tune conversion parameters using “Advanced Settings” (optional, look for the icon).
Our XLS to XLSX Converter is free and works on any web browser. We guarantee file security and privacy. Files are protected with 256-bit SSL encryption and automatically deleted after 2 hours.
FreeConvert.com can convert your XLS files to these other formats:
Want to convert large files without a queue or Ads?