GIF is best for images without a lot of detail. Think of simple line graphics. Think of primary colors. JPEG is best for photo-realistic images or images with more detail. The JPEG format reads more colors in the spectrum than does the GIF format. Since a GIF contain less colors, it’s usually smaller in file size. However, a JPEG can be compressed down into a small file size. The concern is image quality. Sharp, clean images like cartoons look better in GIF but photos look like crap. JPEGs can be compressed but will appear blurry if compressed too much.