The Office Open XML Spreadsheet format stores cell values, formulas, formatting, and charts as zipped XML, the default format for Microsoft Excel 2007 and later. Converting to HEIF produces a document file that stores data in the HEIF 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. This makes HEIF the practical choice when the destination system requires it or when the original format is not supported by the target application. 1converter runs this conversion on the server: your file is uploaded encrypted over HTTPS, converted using trusted open-source libraries, and the output is held for 24 hours before automatic deletion.