When a user attempts to follow a broken link or mistypes a url on a website, the user will often be redirected to a typical friendly "404 Not Found" web page so he knows what has happened, instead of throwing some ugly error message.
One way to enhance the experience would be to guess where the visitor intended to go and suggest that page or shows a list of possible pages. An article by the Smashing Magazine describes an approach that makes use of Google's Custom Search API for this purpose. Before embarking onto the implementing it on production, please do note that the free tier for this API has a limit of 100 calls per day.
» A Better 404 Page | Smashing Magazine
One way to enhance the experience would be to guess where the visitor intended to go and suggest that page or shows a list of possible pages. An article by the Smashing Magazine describes an approach that makes use of Google's Custom Search API for this purpose. Before embarking onto the implementing it on production, please do note that the free tier for this API has a limit of 100 calls per day.
» A Better 404 Page | Smashing Magazine