Sandboxed App Caches
macOS sandboxed apps store their writable data inside per-app containers under ~/Library/Containers, where they keep transient files such as NSURLCache web content, WebKit website data, CoreData SQLite journals and WAL files, Quick Look thumbnails, temporary export files, and app-specific logs. These containers exist because App Sandbox restricts direct filesystem access, so each app accumulates its own cache and scratch data over time for faster launches, previews, syncing, and offline content. Kudu removes disposable cache material from sandbox containers while leaving documents, app settings, accounts, passwords, and other personal data untouched.
Why clean Sandboxed App Caches?
- Corrupted NSURLCache or WebKit website data inside a sandbox container can cause blank views, endless loading spinners, or pages that refuse to refresh until the cache is rebuilt
- Old temporary export files and failed download fragments pile up in container tmp and Caches folders, leading to unexpectedly large System Data or app storage usage in Finder and About This Mac
- Stale Quick Look thumbnails and preview caches make documents show outdated previews or generic icons even after the files themselves have changed
- CoreData SQLite stores inside containers can become page-fragmented after heavy churn; VACUUM rewrites the database to compact free pages without deleting rows, which can reduce disk use and improve sluggish list or library loading
- Leftover SQLite WAL and journal files from interrupted writes can keep a sandboxed app reopening slowly or repeatedly reprocessing the same local metadata on launch
- Broken sync and metadata caches in a container can make an app show old badges, duplicate items, or missing recent changes until the local cache is cleared and resynced
- Accumulated app logs and diagnostic traces in container storage can consume gigabytes over time, with the visible symptom being low free space despite no obvious large user files
Cache paths Kudu targets
macOS
~/Library/Containers |
Common questions about Sandboxed App Caches
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Available on Windows, macOS, and Linux. No account required, no feature gates, no telemetry without consent. All cleaning targets are open source and community-auditable.