Portable Document Format (PDF) stores fixed-layout pages with embedded fonts, vector graphics, and page geometry defined by ISO 32000. FB2 file (FB2) stores data in the FB2 format. This reformats the fixed-layout document into a reflowable ebook that adapts to screen size. Metadata such as creation date and embedded colour profiles is preserved where the target format supports it. The result is a standard FB2 file readable by any compatible application. 1converter handles PDF-to-FB2 conversion server-side: files are uploaded over HTTPS, processed on isolated cloud infrastructure, and the converted output is available for download for 24 hours before automatic deletion. No account is required for standard conversions.