The ZST file format stores data in the ZST format. Converting to ISO produces a archive file that stores data in the ISO format. This packages the document into a compressed archive for smaller transfer size. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. This makes ISO 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.