From the article: Custom 404 Page - Web Design Portfolio Project
There are many elements of a great 404 page. They should be interesting, engaging, relevant to the rest of the site and helpful. What do you think is most important about a good 404 page? What makes a "not found" page great? Finish the sentence
404
- On a 404 i would place at least a search bar, the navigation, a sitemap or products sitemap in case of an e-commerce store. An short explanation why the visitor got this 404-page in the first place.
- —Guest richard blezer
Links!
- If a visitor hits a default (or a linkless customized) error page, they are most likely to leave the site via the "Home" or "Back" buttons on their browser, which isn't good at all for the site. As a minimum, links for the site's home and/or sitemap should be provided. A search box with a relevant default value (based on the wrong URI) is a plus, and should be added whenever possible. In addition, for highly dynamic pages where most URIs are handled by a bunch of server-side scripts (either beautified or not), some heuristics are in order: if the scripts can figure out some "best match" for the URI, then that match should be served with some notice explaining the error (and, of course, with a 404 status, so machines know what's going on). I started doing this with my own site and noticed huge improvements (90% of visitors leaving the site where from error pages, now the %s are very evenly and most (90% ) visitors browse at least 8 pages in the site before leaving!).
- —Guest Eduard Pascual
404 Page
- Site Map, because will show your visitor what you have in your site with direct link !
- —moradian
Error 404
- I place this 404 Error page on all sites I design: http://www.billwilliams.org/error.html
- —B.Williams
Check out Google's 404 Widget
- This is straight from Google's website: The 404 widget is a quick and easy way to embed a search box on your custom 404 page and provide users with useful information designed to help them find the information they need. Where we can, we'll also suggest other ways for the user to find the information they need, thus increasing the likelihood that they'll continue to explore your site. Get it here: http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=93644
- —Guest RickH

