There are various "lite" or mobile-optimized fan versions, such as those by theonegolikes3332 , which are often free to download. What to Expect in Chapter 4: Safe Haven
The official Chapter 4 continues the dark saga of the factory. Poppy Playtime Wiki
The official release is primarily hosted on Steam and Epic Games . itchio poppy playtime chapter 4 free
If you search for "Poppy Playtime Chapter 4 free" on itch.io, you will encounter various community-made projects. These are not official but offer a way to engage with the lore for free:
Everything You Need to Know About Poppy Playtime Chapter 4 on itch.io There are various "lite" or mobile-optimized fan versions,
In short, no. The official developed by Mob Entertainment is a paid expansion.
Many independent creators use assets to build their own visions of Chapter 4. For instance, Pizx released a Poppy Playtime Chapter 4 fan game as a small project using a starter kit. If you search for "Poppy Playtime Chapter 4 free" on itch
While Mob Entertainment has a profile on itch.io, the fourth chapter is not available as a free download there.