Dragging an app to the Trash removes the binary — and almost nothing else. Preferences, containers, caches and helper files stay behind. For a single app that's megabytes; for a habit of installing-and-forgetting, it's gigabytes of "System Data" you can't explain.
For an app called "AppName", check these after moving the .app to Trash:
| Location | Typical size | Notes |
|---|---|---|
~/Library/Application Support/AppName | 100 MB – 10 GB+ | The big one — AI apps keep models here |
~/Library/Caches/com.vendor.AppName | 10 MB – 2 GB | Safe to delete |
~/Library/Containers/com.vendor.AppName | varies | Sandboxed apps store everything here |
~/Library/Preferences/com.vendor.AppName.plist | KBs | Settings; harmless but tidy to remove |
~/Library/Logs/AppName | 1 MB – 500 MB | Often forgotten |
Shortcut: in Finder press ⇧⌘G, paste ~/Library, and search for the vendor name. Also check /Library (no tilde) for system-wide helpers, and launch Terminal → launchctl list | grep -i vendor for background helpers.
If you install more than a couple of apps a month, manual hunting doesn't scale. Dedicated uninstallers watch installations and remove the leftovers in one click:
| App | Approach | Free tier |
|---|---|---|
| AppCleaner (FreeMacSoft) | Drag-and-drop leftover hunt | 100% free |
| MacCleaner PRO (Nektony) | Suite: uninstaller + duplicates + disk space | Trial, paid bundle |
| CleanMyMac (MacPaw) | Uninstaller + general cleanup suite | Trial, subscription |
Our take: AppCleaner for free, and a suite like MacCleaner PRO once you're also fighting caches and duplicates — it bundles the uninstaller with the rest of the cleanup toolkit, which is what most people actually need.
Claude Code, Cursor and Ollama keep gigabytes in non-obvious places even after "uninstalling". Follow the per-tool guides in our cleanup hub before you reinstall — otherwise the new install inherits the old bloat.