Unity Caches: How to Reclaim Gigabytes Without Breaking Your Projects

The Library folder: your biggest win, if the editor is closed

Inside every Unity project sits a Library folder — the editor's private cache of imported assets, generated code and build artifacts. It routinely dwarfs the Assets folder it serves: import 500 MB of textures once and Library stores its own processed copies of them. The folder is disposable by design; delete it and Unity rebuilds it on the next open, at the cost of a long reimport.

Two rules keep this safe. Never delete Library while the project is open — the editor holds files there and may write corruption on exit. And treat a Library rebuild after a Unity version upgrade as inevitable anyway, because the caches are keyed to the engine build and rarely survive it.

The full map of Unity's disk appetite

Library is the loudest offender, but far from the only one. Unity scatters caches across the user profile and the editor itself, and none of them show up in the project folder. Here is where a typical installation hides its gigabytes.

• <Project>\Library — imported assets and artifacts; safe to delete with the project closed, fully regenerated on next open
• %LOCALAPPDATA%\Unity\cache — Package Manager and Global Illumination caches shared by every project on the machine
• %APPDATA%\Unity\Asset Store-5.x — legacy Asset Store downloads, re-downloadable at any time
• Unity Hub → Installs — each editor version takes several gigabytes; archive the ones you no longer use
• %USERPROFILE%\.gradle — Android build machinery that grows with every target SDK
• <Project>\Library\Bee and Temp — incremental build artifacts, wiped out by a clean rebuild

A routine that never breaks a project

Make it a quarterly ritual, and always with the editor closed. Strip Library and Temp from projects you archive, and prune retired editor versions in Unity Hub. Clear the Package Manager cache only when a package genuinely misbehaves — reinstalling everything otherwise costs more time than the gigabytes are worth.

Keep two things sacred: Assets and ProjectSettings are the actual project, and no cache cleanup should ever touch them. Windows-side temp folders can be delegated to a cleaner like Kleaner PRO, but the Unity-specific paths above are yours to manage — the editor will never tidy up after itself. Teams that build a lot should look at Unity Accelerator, a shared cache server that stops five workstations from importing the same assets five times.

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