A different cryptogram is shown at the very end of the credits of every episode.
A reversed voice message code is the heard at the very end of the opening theme song when the "Gravity Falls" title and the "created by Alex Hirsch" credit zoom in. The message changes after a number of episodes.
Starting with Season 2, a cryptic image with a number code shown on a page of a book is shown before the Disney Television Animation logo appears.
All the episodes (except weirdmageddon 3:take back the falls) contain an extra scene during the credits that usually continues something from what happened earlier depending on what episode.
After the credits in "weirdmageddon 3:take back the falls" a glimpse of a real life Bill Cipher statue is shown. This brief shot was teasing a worldwide treasure hunt to find the statue known as "The Cipher Hunt" which was organized by the creator of Gravity Falls, Alex Hirsch and took place from July 20-August 2, 2016.