Blender caches simulations and renders beside your project, in full
Physics caches, render output and packed textures make a .blend file the smallest part of a project. Where each lives and what to clear.
A .blend file is usually small. What surrounds it is not: baked physics simulations, render output, and any textures you packed into or beside the project. On a Mac used for animation this is one of the fastest growing folders there is.
Where Blender writes things
| What | Default location | Regenerated |
|---|---|---|
| Physics and fluid caches | A cache folder beside the .blend | Yes, by rebaking |
| Render output | The output path in settings, often /tmp | No, once you delete it |
| Temporary files | The temp directory in preferences | Yes |
| Packed resources | Inside the .blend itself | Not applicable |
| Auto saves | Temp directory | Yes |
du -sh ~/Documents/*blend* ~/Desktop/*blend* 2>/dev/null | sort -h | tail
find ~ -maxdepth 5 -name 'blendcache_*' -exec du -sh {} + 2>/dev/null | sort -h | tailBaked simulations are the large ones
A fluid or smoke simulation writes a file per frame, and a few hundred frames at high resolution is tens of gigabytes. Blender keeps them so playback is instant, and they are only useful while you are working on that shot. Freeing the bake inside Blender is the correct removal, since the project then knows the cache is gone.
The temp directory
Blender's temporary directory defaults to the system temp location, which on macOS is cleared on restart. If you have pointed it somewhere permanent, it accumulates auto saves and render temporaries indefinitely, and it is worth checking:
# Blender: Preferences, File Paths, Temporary FilesRender output you have already delivered
Image sequences are the other half. A finished render exists as the video you exported, and the thousands of frames it came from are usually kept out of caution. That is the same decision as render caches in a video editor: keep the export, archive the project, remove the derived frames.
Common questions
Where does Blender store its cache on a Mac?
Physics and fluid caches go to a blendcache folder beside the .blend file by default, temporary files to the path set in preferences, and render output to whatever path is configured in output settings.
Can I delete Blender's physics cache?
Yes. Use Free Bake inside Blender so the project knows the cache is gone, and rebake when you need it. Baked simulations are usually the largest part of a Blender project.
Why is my Blender project folder so large?
Baked simulations and rendered image sequences, not the scene file. A .blend is usually small unless resources are packed into it, while a few hundred simulation frames can be tens of gigabytes.
Where is Blender's temporary directory on a Mac?
It defaults to the system temporary location, which macOS clears on restart. If it has been changed to a permanent path in preferences, auto saves and render temporaries accumulate there indefinitely.