HTM is a document format: it stores data in the HTM format. XLSX is a spreadsheet format that stores cell values, formulas, formatting, and charts as zipped XML, the default format for Microsoft Excel 2007 and later. This extracts structured tabular data from the document into an editable spreadsheet format. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. Converting between these two formats is common when the source application does not support XLSX natively or when the target platform only accepts XLSX. 1converter processes this conversion server-side using open-source tools. Files are transferred over HTTPS, converted on secure cloud servers, and automatically deleted after 24 hours.