Benjamin Mayo, 9to5Mac:

Mixpanel reported that Apple had crossed the magic 50% milestone for iOS 12 at the weekend, and now Apple has released its first usage numbers which are based off visits to the App Store.

Apple says 50% of all devices are running iOS 12, and 53% of devices introduced within the last four years. This four year timespan metric is new, and it means that it only counts devices launched since September 2014 (iPhone 6 and later).

I would bet that these numbers would be even higher if there weren’t so many 8GB and 16GB phones out there. When your phone is full, it is no trivial matter to update to a new version of iOS.

Given that the absolute smallest capacity of Apple’s new line of phones is 64GB, I’d expect transition to new versions of iOS to come a lot faster over time, and for adoption rates to soar as older, smaller phones drop out of usage.

Side note: Here’s an Apple Support document talking you through updating your phone if space is an issue.