C# API To Convert OTT To XLSB or Online App without using Microsoft Excel or Adobe Reader or online. Test free OTT To XLSB online converter quickly before integrating the code....including OTT, HTML, DOC, DOCX, PDF, ODT, RTF, TXT, and more. Once...spreadsheet formats, including XLSB, XLSX, XLSM, CSV, HTML, ODS, and more...