The two main graphic formats that Web browsers can read are GIF and JPEG. Each is suitable for different types of images, so it is important to know which one to choose.
GIF is a graphic format using a compression designed by CompuServe. They have the extension ".gif" and are best used for illustration, line art and simple graphics that have little or no shading. They support up to 256 colors and use a lossless compression which allows for all detail to be maintained during the compression process. Most clip-art and text-based images on the Web are of the GIF format.
JPEG is a graphic format designed by Joint Photographic Experts Group (JPEG). They have the extension ".jpg" and are best used for photographic images. JPEG files can support up to 16 million colors as compared to GIF's 256 colors. It uses a lossy compression which means certain parts of images are permanently thrown away so that the files take up less storage space. Most photographic images on the Web are of the JPEG format.
Making smaller images.
Reducing colors in your images.
Subscribe to the URI Web Publishing Blog for latest news, tips, resources and tools related to web technologies.
Subscribe to URIWEB-L Listserv to keep informed of ideas on web-related issues on campus.