The Security and Clutter Risk
Safari on macOS has a long-standing feature designed for user convenience: it automatically opens “safe” files immediately after downloading them. This category includes movies, pictures, sounds, PDF and text documents, and notably, `.zip` archives. When you download a zip file, Safari will silently extract its contents into your Downloads folder and often move the original `.zip` archive to the Trash. While this saves a double-click for simple documents, it is a significant security risk for executable software, and it creates massive clutter if you are downloading large project archives that you intended to keep compressed for later storage.
Disabling Safe File Auto-Opening in Safari
To stop macOS (specifically through Safari) from automatically unzipping your downloaded archives and opening files without your explicit permission, you need to change a core browser preference.
Launch the Safari web browser. In the top menu bar, click on the word Safari (next to the Apple logo) and select Settings… from the drop-down menu. Ensure you are on the General tab (it usually opens to this by default). Look all the way at the bottom of the General settings window. You will see a small checkbox labeled Open “safe” files after downloading. Uncheck this box. You can now close the settings window. From this point forward, Safari will simply download files and leave them exactly as they are—as `.zip`, `.pdf`, or `.mp4` files—resting safely in your Downloads folder until you actively choose to double-click and open them.