macOS Background Download Session Cache (com.apple.nsurlsessiond)
nsurlsessiond caches incomplete background file downloads for system apps and iCloud daemon sync. Clearing the cache is safe.
macOS Files
macOS system files and application support
macOS Font Server Cache (/var/db/ats)
Apple Type Services (ats) caches font rendering metrics. Resetting the font cache fixes corrupted font glyphs and system text glitches.
macOS System Font Cache Directory (com.apple.fontd)
macOS caches system and user font rendering structures in com.apple.fontd. Learn how to reset macOS font cache to fix garbled text.
Homebrew Package Cache (~/Library/Caches/Homebrew)
Homebrew caches downloaded bottle binaries (.tar.gz) and source code archives. Purging the cache via brew cleanup is safe.
macOS iCloud Drive Sync Engine Container & Cache (bird)
The macOS background daemon bird manages iCloud Drive file syncing and caches staged cloud downloads in ~/Library/Caches/com.apple.bird. Learn how to clean bird cache.
Apple Mail Downloads Cache (Mail Downloads)
The Mail Downloads folder caches copies of email attachments opened in Apple Mail. Deleting old downloads is safe.
Apple Messages Attachment Cache (~/Library/Messages/Attachments)
The Messages Attachments folder stores local copies of all photos, videos, and voice notes received in iMessage. Deleting attachments is safe.
macOS Metal Shader Cache (~/Library/Caches/com.apple.metal)
The com.apple.metal directory caches pre-compiled Metal graphics shaders on Apple Silicon and Intel Macs. Deleting it is safe.
How to Fix 'Operation Not Permitted' When Deleting Files on macOS
Fix Terminal 'Operation not permitted' errors when deleting files on Mac by granting Full Disk Access or managing SIP permissions.
macOS Photos.app Analysis & Facial Recognition Database (mediaanalysisd)
macOS background process mediaanalysisd stores facial recognition, object detection, and visual search index databases in ~/Library/Containers/com.apple.mediaanalysisd. Learn how to manage it.
Safari LocalStorage Web Database (~/Library/Safari/LocalStorage)
The Safari LocalStorage folder caches HTML5 offline data and database files for visited websites. Deleting LocalStorage is safe.
macOS Screen Capture UI Temp Folder (com.apple.screencaptureui)
The screencaptureui temporary directory caches unrendered video frames during Mac screen recordings. Deleting temp files is safe.
macOS System Update Packages (/Library/Updates)
The /Library/Updates folder holds downloaded macOS system installer packages (.pkg). Deleting downloaded update packages is safe.
macOS Spotlight Search Index Database (.Spotlight-V100)
macOS stores Spotlight search metadata index databases in .Spotlight-V100 at the root of every drive. Learn how to rebuild Spotlight index safely.
The 2026 macOS System Data Storage Bible: Reclaim 100GB+ Safely
The ultimate 2026 master guide to finding and deleting hidden macOS System Data bloat, including user caches, Time Machine APFS snapshots, Xcode artifacts, and Docker containers.
Xcode visionOS & Apple Vision Pro Simulator Runtime (visionOS.simruntime)
Xcode stores Apple Vision Pro visionOS simulator runtimes in /Library/Developer/CoreSimulator/Profiles/Runtimes. Learn how to clean visionOS simulator images.
macOS App Containers Folder (~/Library/Containers)
The Containers folder stores App Store sandboxed data, caches, and local databases. Selective deletion of uninstalled app containers is safe.
macOS Application Support Folder (~/Library/Application Support)
Application Support stores app user data, extensions, and local databases. Selective cleanup of uninstalled app folders is safe.
macOS Launchd Caches (~/Library/Caches/com.apple.launchd)
com.apple.launchd stores user-level launch daemon caches on macOS. Deleting launchd caches is safe and resolves launch agent glitches.
macOS Core Dumps Folder (/cores)
The /cores folder in macOS holds memory dumps generated when Unix processes crash. It is completely safe to delete and frees up space.
macOS DiagnosticReports Folder (~/Library/Logs/DiagnosticReports)
DiagnosticReports stores app crash reports and panic logs on Mac. Deleting old log files is completely safe and cleans up system clutter.
MobileSync Backup Folder (macOS iPhone & iPad Backups)
MobileSync/Backup stores local iPhone and iPad backups on your Mac. Deleting old backups is safe and frees up massive SSD storage.
macOS MobileSync Backup Folder (~/Library/Application Support/MobileSync/Backup)
MobileSync/Backup stores local iTunes and Finder iPhone/iPad backup archives. Deleting old backups is safe and frees massive Mac SSD storage.
macOS QuickLook Thumbnail Cache (com.apple.QuickLook.thumbnailcache)
com.apple.QuickLook.thumbnailcache stores cached Finder image and video preview thumbnails. Clearing QuickLook cache is safe and fixes broken previews.
macOS Saved Application State Folder (~/Library/Saved Application State)
Saved Application State stores window state snapshots for Mac apps. Deleting it is safe and fixes apps stuck in infinite crash-restart loops.
macOS Local Time Machine Snapshots (MobileBackups)
Local Time Machine Snapshots store offline backup points on Mac SSDs. Deleting local snapshots via tmutil is safe and recovers tens of gigabytes.
macOS Private Temp Folder (/var/folders)
/var/folders is the private system temp directory for macOS. Clearing temp files when apps are closed is safe and reclaims lost storage.
.DS_Store
A hidden macOS file that stores folder view preferences. Completely safe to delete, though your Mac will just create a new one.
Is It Safe to Delete iOS Software Update Files on Mac?
iOS Software Update files are massive installers left behind on your Mac after updating an iPhone. They are completely safe to delete to save space.
Is It Safe to Delete Library/Caches?
The Library/Caches folder stores temporary files to help your Mac apps load faster. It is completely safe to delete to reclaim gigabytes of storage space.
Is It Safe to Delete sleepimage?
The sleepimage file allows your Mac to safely hibernate without losing data if the battery dies. Deleting it is safe, but it will immediately come back.
Is It Safe to Delete .Spotlight-V100?
The .Spotlight-V100 folder is a hidden macOS indexing directory. Deleting it forces your Mac to rebuild its search index, which can fix Spotlight search bugs.
Is It Safe to Delete .Trashes?
The .Trashes folder is a hidden directory on macOS and external drives that holds deleted files. Deleting it permanently removes those files and reclaims space.