Why scrolling in Safari on iOS 11 suddenly feels much faster

Adaptive inertial scrolling unfurls a page faster the quicker you fling, and thus allows you to reach to the end or the middle of a long page in a jiffy, as any avid reader on an Android phone would attest. Mobile Safari supports this option, but until now web devs had to enable it in their HTML code, and the vast majority overlooked this requirement, even on some of the most popular websites. This made scrolling through long web pages on your iPhone's screen a pain, as no matter how hard and fast you swiped on the screen, the page barely moved with one set small distance, annoying the heck out of those who'd seen better, and requiring multiple swipes to reach to where you left off, instead of one or two. This usually irks only folks coming from Android, as iOS users have apparently developed muscle memory for Safari's out-of-tune scrolling efforts. This is how it used to be:

All the more ironic, since Apple has been having inertial scrolling since the OG iPhone, has patents on it, and even accused Samsung of stealing it during the great patent wars of 2012. 

With iOS 11, however, Safari now enables the acceleration option to the whole of each and every website by default. No need to code it in, and suddenly the entire web on your iPhone scrolls in the fast and smooth manner that the rest of the iOS system does, and has been so praised for. There you have it - one major gripe of Android users who switch to an iPhone has now been remedied, and that's not all there is to iOS 11 and its laundry list of new features.

source: Daring Fireball & FerdyChristant