The version of Safari that ships with OS X 10.11 ‘El Capitan’ allows web developers to build custom experiences that work with Force Touch input, similar to how native app developers have had access to that new hardware before now. That means that you can set custom actions for how content on your web page responds to deeper clicks on the trackpads that ship in Apple’s newest notebooks, including the MacBook and MacBook Pro with Retina Display.
Apple’s Force Touch trackpad enables a pressure-sensitive additional level of input beyond a standard click, which Apple uses to provide dictionary definitions, Maps views, link previews and more for any and all current standard text displayed in Safari.
The new Force Touch tools allow devs to use that new type of input to do things like trigger animations, or even enable actions, such as favoriting or starring content in a matrix or list, for example. Behind the scenes, it works like registering a mouse click, but adds a second level.
It’s basically a good way to add shortcuts to website functions and features that might otherwise be hidden behind menus or in additional pages, and a way to introduce creative animations and transitions that add to the enjoyment of the overall browsing experience. Using it in any capacity beyond the additive is potentially risky, since not everyone visiting a site is going to have a Force Touch device, however.
Still, it’s an interesting new ability, and one that could theoretically work just as well on iOS – were any iOS hardware sporting Force Touch currently. Rumors abound that it will make an appearance with the next generation of hardware, and the flexibility of this new Safari feature certainly doesn’t discount that speculation.