Because extensions can modify the behavior of Safari, you should download and install extensions only from trusted sources.
Note:Extensions are available only if you have Mac OS X v10.5 Leopard or later. For information on upgrading Mac OS X, go to the Mac OS X website.
To download and install extensions:
Choose Safari > Preferences and click Extensions.
Click Get Extensions.
On the extensions webpage, follow the instructions to download and install one or more extensions.
To update your extensions:
Choose Safari > Preferences and click Extensions.
Click Updates.
Click the Install button for the extension you want to update, or click Install All Updates.
To have updates installed automatically whenever they’re available, select Install Updates Automatically.
To turn off or uninstall extensions:
Choose Safari > Preferences and click Extensions.
Click the On/Off switch to turn all extensions off.
Click the Uninstall button for an extension you want to remove.
Any changes you make to extensions, including installing and uninstalling extensions, take affect when you navigate to a new webpage or refresh the current page.