The JPEG Image format uses lossy DCT compression that permanently discards fine pixel detail to achieve small file sizes, ideal for photographs. Converting to ICO produces a image file that bundles multiple raster images at different resolutions (16x16 through 256x256) into a single file for use as application icons. This conversion changes the file's encoding, compression method, and supported feature set. Colour profiles and orientation metadata are preserved in the output. This makes ICO the practical choice when the destination system requires it or when the target format offers better compatibility or compression. 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.