Many of your visitors may not have browsers enabled for viewing these techniques. Some with browsers that are capable of viewing Java or having plug-ins will have these functions turned off for security or other reasons. Frames Web pages are small to begin with and carving them up with frames can reduce the usable area to a tiny fraction of the screen. Frames frequently make printing a page difficult or impossible. Frames make bookmarking specific pages difficult for the viewer.
Frames can make navigation out of a site frustrating for the viewer.
Frames can cause unexpected results when a search engine indexes your site. A visitor may be sent into your site via somewhere other than your home page. Testing and validation Test your pages with several different browsers. Be sure to test using the major online services such as AOL and Prodigy. Test your pages with the option to view images turned off.