SK1 file (SK1) stores data in the SK1 format. NEF file (NEF) stores data in the NEF format. This renders each page as a raster image, making the content viewable without a document reader. Each page is rendered at the specified DPI and saved as a separate image; text in the output is no longer selectable. The result is a standard NEF file readable by any compatible application. 1converter handles SK1-to-NEF 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.