Use the Extensions pane of Safari preferences to manage extensions.
Off/On switch
To turn all extensions on or off, click the switch. For certain extensions, the change will not take effect until you navigate to a new page.
Extensions list
All your installed extensions are listed. If updates are available, an indicator appears at the bottom of the list.
Extension Updates
Any updates available for your extensions are listed in the box on the right.
To automatically install updates whenever they’re available, select Install Updates Automatically.
To manually install all available updates, click Install All Updates.
To manually install a single update, click its Install button.
Get Extensions
To view extensions available for Safari, click this button. A webpage opens providing a list of extensions, including descriptions and instructions for downloading and installing them.