XLSX (EXCEL) to OTB Converter
Convert your xlsx files to otb online & free
Office Open XML Worksheet Sheet
How to convert XLSX to OTB
Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.
Choose "to otb"
Choose otb or any other format you need as a result (more than 200 formats supported)
Download your otb
Let the file convert and you can download your otb file right afterwards