Finding specific things

The Application Support surprise

Updated 2026-07-31 · 4 min read

Application Support is where apps keep real data, and where uninstalled apps leave it behind for years.

Size it

du -h -d 1 ~/Library/Application\ Support 2>/dev/null | sort -hr | head -25

The offenders are predictable: messaging apps caching media, Electron apps (Slack, Discord, VS Code), design tools, and folders belonging to apps you deleted long ago.

The usual heavy hitters

• MobileSync — iPhone/iPad backups made by Finder/iTunes, often the single biggest item
• Electron app caches — Slack, Discord, Teams, each hundreds of MB to gigabytes
• Adobe — Creative Cloud caches and libraries
• Orphans — full data folders from apps no longer installed

Finding orphans

Data whose app is gone:

ls ~/Library/Application\ Support | while read app; do
  echo "$app"
done

Cross-reference names against /Applications. A folder named for an app you cannot find is a deletion candidate — but check it holds no documents first.

iPhone backups specifically

du -sh ~/Library/Application\ Support/MobileSync/Backup/* 2>/dev/null

Manage these through Finder (device → Manage Backups) rather than deleting blind — but old backups of devices you no longer own are pure waste.

What is safe

• Orphaned folders from uninstalled apps, after confirming no documents inside
• Old device backups you do not need
• Electron Cache/GPUCache subfolders (apps rebuild them)

What is not

• Anything for an app you use — this is its real data, not cache
• Folders you cannot identify — research before deleting
• License and activation data — some apps store entitlement here

Because it is inside ~/Library, none of this appears in Spotlight, which is exactly why it grows unwatched. A periodic du on this one folder catches more reclaimable space than most whole-disk tools.

Common questions

Why is Application Support so large on my Mac?

App data, Electron caches, and iPhone backups accumulate there — plus data left by uninstalled apps. du -h -d 1 on the folder ranks them.

Is it safe to delete folders in Application Support?

Orphans from uninstalled apps and caches, yes. Folders for apps you still use hold real data — leave them.