Tap to preview links in Safari for Mac OS X
Force Click trackpad not required.
When browsing about the Web, I often open links I come across in new tabs in the background, which can leave me with too many open tabs to keep track of after an embarrassingly short time. I am easily distracted but also gamely attempt to finish what I'm reading before jumping to the next thing. With Safari and a trackpad setting enabled on my Mac, I can quickly preview links without leaving the page I'm currently on or opening yet another tab.
To enable this preview ability, go to System Preferences > Trackpad. Click on the Point & Click tab at the top if you aren't there already, and then check the box for Look up & data detectors.
With this setting checked, a three-finger tap on a link will open a small window to let you preview the webpage behind the link. On this preview window, you can scroll to read the entire page, if you want to do more than just a quick preview. You can click in the preview window to open the page in a new Safari tab, or you can click outside of the window to close the preview window.
You will need a multitouch trackpad to perform this maneuver, but you do not need a newer Force Click trackpad.
This trackpad setting also lets you three-finger tap on a plain-text words to look up their dictionary definition. In Chrome, a triple-tap looks up the definition of words for both plain text and hyperlinked text -- it does not preview links. As for Firefox, its does not support this trackpad setting. I tested all Chrome, Firefox and Safari on an older MacBook Pro running OS X 10.11 El Capitan.
(Via OS X Daily)