Safari for Mac: Block pop-ups and unnecessary content in Safari
You can prevent webpages from displaying pop-up windows or loading time-consuming content that may be unnecessary. However, blocking pop-ups and unnecessary content might also block some content you want to see, or features like animation.
Choose Safari > Preferences, then click Security.
Select what to block:
Pop-up windows: Select “Block pop-up windows.”
Plug-ins: Deselect “Allow Plug-ins.”