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NSCachesDirectory

NSCachesDirectory is the search-path constant for an iOS app's Library/Caches folder, where apps store regenerable data like downloaded images and computed files. Its contents are purgeable: iOS can delete them under low-storage pressure, and they are excluded from iCloud and iTunes backups.

iOS developmentiOSiPadOS

NSCachesDirectory

Also known as: caches directory ios, library caches

NSCachesDirectory is the search-path constant for an iOS app's Library/Caches folder, where apps store regenerable data like downloaded images and computed files. Its contents are purgeable: iOS can delete them under low-storage pressure, and they are excluded from iCloud and iTunes backups.

  • NSCachesDirectory resolves to Library/Caches inside the app sandbox.
  • Its contents are excluded from iCloud and computer backups.
  • iOS can purge Caches automatically under low-storage pressure, usually while the app is idle.

What NSCachesDirectory is

NSCachesDirectory is a FileManager.SearchPathDirectory constant that resolves to <app sandbox>/Library/Caches. Apps obtain the URL with FileManager.default.urls(for: .cachesDirectory, in: .userDomainMask). The folder is meant for data the app can recreate, such as thumbnails, decoded media, and network downloads.

Unlike Documents, the Caches folder is not backed up to iCloud or a computer. Apple's guidance is that anything which would be inconvenient (but not impossible) to lose belongs here, keeping backups small and fast.

Purgeable behavior and cleanup

iOS treats Caches as purgeable space: when device storage runs low, the system can delete files from any app's Caches folder, typically when that app is not running. Apps must therefore handle missing cached files gracefully and regenerate them on demand.

Because the system only purges under pressure and may not reclaim everything, this folder is a primary target for an in-app cleaner. An app can enumerate Library/Caches with FileManager and call removeItem(at:) to clear its own cache immediately, reporting the freed bytes to the user. Apps cannot delete other apps' Caches; only the system does that.

Related terms

Keep reading the reference.

iOS developmentFileManager (iOS)FileManager is the Foundation class iOS apps use to read, create, move, copy, and delete files and directories inside their sandbox. It exposes URLs for system locations (Documents, Caches, tmp) and reports per-file size and dates, so a storage cleaner relies on it to enumerate and remove reclaimable files.iOSiPadOSMacPurgeable spacePurgeable space is storage that macOS can reclaim automatically when the disk fills up — mainly caches, regenerable files, and cloud-stored content that has already been uploaded. It still appears used, but macOS frees it on demand rather than failing a write.macOSStorage conceptsApp cacheAn app cache is temporary data an app stores to load faster — images, thumbnails, streamed media, and web content. Clearing it is safe: the app simply re-downloads what it needs the next time you use it.iOSAndroidGeneraliOS developmentURLCacheURLCache is Foundation's in-memory and on-disk cache for HTTP and HTTPS responses fetched via URLSession. It stores response data keyed by request so repeat network calls can be served locally. Apps can inspect its current size and clear it, which a storage cleaner uses to reclaim network cache.iOSiPadOS

Act on it

Guides and tools for this topic.

Clean up phone storageCleanor for iOS