XLSX is a spreadsheet format: it stores cell values, formulas, formatting, and charts as zipped XML, the default format for Microsoft Excel 2007 and later. HDR is a document format that stores data in the HDR format. This converts the tabular data into a fixed-layout document suitable for printing or sharing. 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 HDR natively or when the target platform only accepts HDR. 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.