Steps to  show open tabs on other devices on Mac Safari:

• Launch Safari.
• Select Tabs from the drop-down menu.
• To get to the bottom of the list, scroll down. A list of open tabs from your other supported devices appears below the images of tabs open on your device.
• Select the one you wish to open by tapping it.

• Click the Tab Overview icon in the Safari software on your Mac.
• You can view what's open on your Mac, as well as a list of what's open on your other devices.
• To open a web page, simply click on it.
• Tip: You can also use the Smart Search form to enter a portion of the page's name, then click the page in the iCloud Tabs section of your search results.

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