WhatsApp's Mac app mirrors whatever your phone previews — and caches all of it locally. Group chats with auto-download on can push the local store past 10 GB before you notice anything.

Locate it

du -sh ~/Library/Group\ Containers/group.net.whatsapp.WhatsApp.shared 2>/dev/null
du -sh ~/Library/Group\ Containers/group.net.whatsapp.WhatsApp.private 2>/dev/null

The shared container holds the media store; MessageStore databases sit in the private one. On newer builds the app data can also appear under ~/Library/Containers/WhatsApp.

Clear it the supported way

In WhatsApp → Settings → Storage and Data → Manage Storage: the app lists large files and forwards, and cleaning there never touches chat history. Use it before reaching for the terminal.

If you must clear manually (app fully quit first): delete files inside the media folders of the shared container, never the databases or plist files beside them. Deleting databases logs you out and can force a re-link.

Stop the regrowth at the source

The Mac client has no auto-download settings of its own — the phone drives it. On the iPhone: WhatsApp → Settings → Storage and Data → turn off photos in auto-download for groups (keep contacts if you like), and run Manage Storage there monthly. The Mac cache then grows at a crawl instead of a gallop.

The chat-app cleanup family

Telegram (guide), Slack and Discord (guide) share the same disease with different paths. For everything else hiding on the disk, System Data explained is the map, and the estimator ranks your own suspects in ten seconds.