https://chrome.google.com/webstore/detail/wayback-machine/fpnmgdkabkmnadcjpehmlllkndpkmiak
https://addons.mozilla.org/en-CA/firefox/addon/wayback-machine_new/
It will also detect when a webpage you are trying to visit is dead and will offer to replay an archived version
I believe the automatic archiving has to be manually enabled by going to the settings, selecting the general tab and enabling “Auto save page”.
Thanks, I just looked at my settings and realized that I hadn’t checked that box.