FB2 is a ebook format: it stores data in the FB2 format. PDF is a document format that stores fixed-layout pages with embedded fonts, vector graphics, and page geometry defined by ISO 32000. This converts the reflowable ebook layout into a fixed-page document 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 PDF natively or when the target platform only accepts PDF. 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.