Closing a window does not quit the app
The red dot leaves the app running. Command-Q is what actually closes it, and the Dock tells you which is which.
Works on: macOS Ventura 13 and later · checked on macOS Golden Gate 27
Published: · Source: Rod Herzstrom
Click the red dot and the window goes away, but the app is still running: still in memory, still in ⌘ + Tab, occasionally still making noise. On Windows, closing the last window ends the program; here it does not.
The Dock keeps score. A small dot under an icon means that app is open, window or no window. To really quit, press ⌘ + Q.
It is deliberate, not a leak. An app left loaded reopens instantly, and a few of them — Mail, Messages — are designed to keep working with no window at all. The one time it matters is when something misbehaves: quitting properly is what restarts it clean.
If you cannot see the dots, turn on Show indicators for open applications in System Settings → Desktop & Dock.
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