The Internet Archive today is launching a free service to help webmasters improve their user experience by augmenting their website’s 404 Page Not Found page to link to the Wayback Machine in the case that it has it. Therefore users trying to get to any pages that might have been on a previous version of your website will now be given the option to go to the Wayback Machine.
To embed a link to the Wayback Machine on your site’s 404 pages, just include this line in your error page:
<div id="wb404"/> <script src="https://archive.org/web/wb404.js"> </script>
If an archived page is not found, then nothing will appear, if it is found, then your user will see:
For instance, the Internet Archive has installed this on its 404 error handling page. We had a page, before 2004, that is still referenced on the web. Now, instead of people getting a 404: File Not Found error, they get a page that includes a link to the page in the Wayback Machine.