Safari extensions add functionality to Safari, so you can explore the web the way you want. Extensions can show helpful information about a webpage, display news headlines, help you use your favorite services, change the appearance of webpages, and much more. Extensions are a great way to personalize your browsing experience.
Use the App Store to conveniently download and install Safari extensions. All extensions in the App Store are reviewed, signed, and hosted by Apple for your security.
How to install extensions
Start by installing the latest macOS updates to make sure that Safari is up to date. You need Safari 12 or later to get Safari extensions from the App Store.
Find and install an extension:
- Open Safari and choose Safari > Safari Extensions from the menu bar.
- The App Store opens to the Safari Extensions page, as pictured above. To download and install an extension, click Get or click the price. You might be asked to sign in with your Apple ID.
- Click Install.
- After the extension is installed, click Open and follow the onscreen instructions provided by the extension.
Then return to Safari to turn on the extension you installed:
- Choose Safari > Preferences.
- Click Extensions.
- Select the checkbox next to the extension’s name.
How to turn off or uninstall extensions
Choose Safari > Preferences, then click Extensions.
- To turn off an extension, deselect its checkbox.
- To uninstall an extension, select the extension and click the Uninstall button. If you can’t determine what an extension does, or you don’t expect to use it again, you should uninstall it.
source: Applesupport