Get extensions to customize Safari on Mac
You can install Safari extensions to customize the way your browser works. For example, extensions can help you display social media and news buttons, block content on websites, give you access to features from other apps, and more.
Extensions may access the content of the webpages you visit. Check which extensions you have installed and make sure you’re familiar with what they do.
Tip: The Mac App Store is the safest and easiest way to discover and install extensions. The extensions are reviewed by Apple, and they update automatically when “Install app updates” is selected in App Store preferences.
Installing extensions, and turning them on or off, may take effect immediately or after you go to a new webpage or refresh the current page.
Important: The first time you open Safari, you get warnings about extensions that slow down browsing or are no longer supported:
Extensions that slow down browsing: The extensions will be turned off. You can turn on the extensions in Safari preferences.
Developer-signed .safariextz-style (legacy) extensions: The extensions won’t load and no longer appear in Safari preferences. You can’t turn them on.