Merge XLTX to POWERPOINT Online for Free. Free Online XLTX to POWERPOINT Merger. Merge XLTX to Word, Excel, PPTX, PDF, JPG, HTML, ODS, SVG, XPS and more.... Upload your files, call Workbook.Combine method for merging...import Workbook workbook = Workbook( "Input.xlsx" ) workbook.combine(Workbook(...