GIF vs. JPG, Which to Use?

GIF

GIF (or Compuserve GIF) is one of the two main file types used for images on web pages. It is an index-color format file working with a palette of only 256 colors. GIFs do not use all of the color space available on most web pages since most monitors are set up to show thousands or even millions of colors. GIF images are best when an image is made up of large blocks of single colors like cartoons, line art, flow charts, etc. Use GIFs when:

• your graphic element is made up of solid blocks of color
• you want an animated element
• your image has a transparent background

JPEG

JPEG (or JPG) is the other main file type use for images on the web. JPEGs are best for images that require continuous tone, color blends and a smooth transition between colors. Generally speaking, they will have larger file sizes than GIF images. JPEGs can be saved in a wide range of quality levels. The higher the quality level, the more colors used, and the larger the file size. If you are using JPEGs, you can usually save an image with a medium quality level and still have a good viewable representation of your subject matter. Ordinarily, you shouldn't use the JPEG format with an image with large blocks of solid color. If you do, they tend to look "mushy" with oddly colored pixels around the areas of color change. Use JPEGs when:

• you want to use a photographic image
• your logo or other graphic element has a wide range of colors that must blend into each other

Samples:

	GIF	JPEG
	GIF	JPEG
	The images to the right show how "mushy" a JPEG can become when it is used with an image with large blocks of solid color.