Why are HTML frames bad?

Question

I know they are, but my co-worker doesn\'t believe me. He keeps telling me that Google crawls the inside content and caches it just fine. According to Google, it does crawl

Answer 1

There are various usability and accessibility issues with frames:

1. link can open in the frame it is enclosed in (e.g. a side pane);
2. can break the forward/backward navigation;
3. difficult to bookmark;
4. are not easily searchable (likely to see the content in Google, etc.);
5. break on browsers like Lynx, that are console/terminal based;
6. difficult to size properly (e.g. consuming height on widescreen monitors for banner frames);
7. can break with screen readers and magnifiers (for blind users and visual impaired users);

See http://www.angelfire.com/super/badwebs/ for an example of what not to do.