This page lists retcons given to each series appearing in the web comic 5 Years Later that differ from the canon of their original series.
- Osmos V is a real planet, statements about it not being real were merely lies created by Servantis.
- Vlad's accident in college that gave him his Ghost powers was dated April 7, 1984. In the Danny Phantom episode "Kindred Spirits" a newspaper that was dated June 1983 showed one of Vlad's first crimes he committed as a Ghost.
- The origin of the Egyptian pyramids was changed, now they were designed by the Thep Khufan.
- Kevin Levin is described by Ben to be an alien mutant. Previously it was stated that Osmosians were a subspecies of humans.
- Eon is not an Alternative Ben Tennyson but rather a Chronian possessing the body of one.
- All Chronians have bright, neon skin. This change was made to make Chronians look more like aliens than humans.
- The Ormerowons were renamed to Wrighthers to avoid creating anymore alien species with similar names to their home worlds.
- The Opticoids are confirmed to reproduce Asexuality, they have no genders.
- Astrodactyl uses gastrointestinal fluid to fly rather than star power.
- Toepick uses fear gas to scare his opponents rather than his face looking scary.
- Way Big's red skin is now a hard callus armor peeling off of him, while in the cartoon Way Big's red skin was a cosmic material with metallic properties.