It is important to note that there is no official PDF or physical book for Journal 1 released by Disney or creator Alex Hirsch. While Journal 3 was officially published, Journal 1 remains a fictional object from the show that has not been fully authored for retail.
However, you can find the following "helpful content" created by the fan community: 1. Fan Recreations and Replicas
Because Journal 1 is never fully shown on screen, fans have filled in the gaps with creative "fan-on" (fan-canon) versions:
PDF Recreations: Sites like Scribd host community-made PDFs such as the Gravity Falls Journal 1 Overview by Elderprops, which includes printable pages for bookbinding. Gravity Falls Journal 1 Pdf
Interactive Flipbooks: You can view fan-made versions of Journal 1 on platforms like FlipHTML5.
Physical Replicas: DIY creators on Etsy sell physical hand-made Journal 1 replicas often based on known show pages. 2. Known Content from the Show
If you are looking for what is actually "canon" in Journal 1, the Gravity Falls Wiki maintains a list of all confirmed pages seen in the series. This includes: Journal 1 | Gravity Falls Wiki | Fandom It is important to note that there is
The complete series box set includes a featurette called "The Secrets of the Journals." In this short, Alex Hirsch physically turns pages of the actual prop of Journal 1 used in the studio. You can pause the video and read along. This is the closest you will get to a high-resolution "PDF" legally.
This is the question that splits the fandom.
The Short Answer: No official, studio-released PDF exists. Disney has not digitized Journal 1 for public consumption. the Journal 3 special edition
The Long Answer: Yes, fan-made recreations exist.
Over the last seven years, hyper-dedicated fans (using screenshots from the show, the Journal 3 special edition, and background props from the DVD extras) have compiled what they believe to be the contents of Journal 1. These are unofficial, watermarked, or incomplete.
The subreddit has a "pinned lore document" that is text-only. It contains every word written in Journal 1 from the show’s runtime. While it isn't a pretty PDF with graphics, it is 100% canon and safe.