Some URL shorteners provide a copy of their mappings to the Internet Archive as a promise that if they stop functioning for any reason the archive will continue

Some URL shorteners provide a copy of their mappings to the Internet Archive as a promise that if they stop functioning for any reason the archive will continue to provide the mapping (and make the mapping file available). [0]: https://archive.org/details/301works-faq https://archive.org/details/301works-faq