Both iOS (on the iPhone and iPad) and OS X (on the Mac) let you view open Safari tabs on all your iCloud-connected devices—meaning, for example, you can use your iPhone to see which Safari tabs you have open on your Mac. Neat, right?
But here’s a nifty little twist to that feature for users of iOS 8 and the Mac’s new Yosemite update: now, in addition to viewing open Safari tabs on your other Macs, iPhones, and iPads, you can also close those tabs, too.
On a Mac, just click the “Show all tabs” button in Safari (it’s the button with two squares in the top-right corner of the Safari window), move your mouse over the tab you want to close—say, an open tab on your iPhone—and click the little “X” that appears.
On an iPhone or iPad, tap the “Show all tabs” button, find a tab you want to close on another device, swipe it from right to left, then tap the red “Delete” button.
Within a few seconds or so, the open Safari tab on your other iDevice will disappear, just like that.
Update: Can’t see the open tabs in your other devices? Try this, as noted by The Loop:
First things first, if you want to share tabs between your Yosemite powered Mac and an iOS device running iOS 8, go to Settings > iCloud and make sure the Safari switch is on.