To expand upon this, you can install the web archive extensions which tries to automatically find a website archive if the site you visit is dead (or you can manually select search).

Firefox: https://addons.mozilla.org/en-GB/firefox/addon/view-page-archive/ Chrome: https://chrome.google.com/webstore/detail/wayback-machine/fpnmgdkabkmnadcjpehmlllkndpkmiak