Fewer iPhone users are upgrading to iOS 26 than iOS 18

Apple’s own App Store data for June 2026 shows iOS 26 is on 79% of compatible iPhones, lagging behind iOS 18’s 82% adoption last year. While the update is widespread—running on 86% of devices released in the last four years—its slower uptake has already become

On paper, iOS 26 has made it onto most iPhones. In June 2026, Apple’s App Store data puts it on 79% of all compatible iPhones. But when you look at how that adoption compares to earlier iOS releases, the story turns sharper: fewer people upgraded to iOS 26 than upgraded to iOS 18.

In June 2025, 82% of all iPhones were running iOS 18. By contrast, the share currently on iOS 26 is 79%—a drop that’s small in headline terms, but big enough to stand out among iOS releases since 2015.

Apple says the broader momentum is still real. Of all iPhones, 79% are running iOS 26. For devices introduced in the last four years, the picture looks even stronger: 86% of those newer iPhones have iOS 26 installed.

Yet that “mostly upgraded” snapshot doesn’t erase what the adoption rate suggests. When Apple’s adoption numbers across iOS releases from 2015 through 2026 are lined up, iOS 26 lands with the second-worst adoption rate among iOS updates in that span—only iOS 17 has fewer upgrades.

The exact June adoption rates for iOS 8 through iOS 26, for all compatible iPhones, are:

2015 iOS 8: 84%
2016 iOS 9: 84%
2017 iOS 10: 86%
2018 iOS 11: 81%
2019 iOS 12: 88%
2020 iOS 13: 81%
2021 iOS 14: 85%
2022 iOS 15: 82%
2023 iOS 16: 81%
2024 iOS 17: 77%
2025 iOS 18: 82%
2025 iOS 26: 79%

The report also specifies that these rates are taken in June of each corresponding year, with one exception: iOS 12 usage data was published in August 2019.

At 79%, iOS 26 is also below the 82.3% average adoption from 2015 through 2026. And still, there’s movement. In February 2026, only 66% of all iPhones were running iOS 26—meaning upgrades accelerated in the months that followed.

Even with that improvement, some iPhone owners clearly held back. Apple’s June 2026 App Store data shows 14% of devices are still on iOS 18, while 7% remain on even older iOS releases.

For newer devices, iOS 26 matches iOS 17—at least in the “last four years” bucket Apple publishes every June since 2020. In that category, iOS 26 is at 86%, identical to iOS 17 in 2024. iOS 18, on the other hand, scored higher at 88%. When Apple’s newer-device data from 2019 through 2026 is averaged, iOS 26 also falls below the 87.6% average.

Apple’s exact numbers for “all devices introduced in the last four years,” starting from when the company released this data in June, are:

2019 iOS 12: 85%
2020 iOS 13: 92%
2021 iOS 14: 90%
2022 iOS 15: 89%
2023 iOS 16: 90%
2024 iOS 17: 86%
2025 iOS 18: 88%
2026 iOS 26: 86%

If iOS 26 has lagged behind iOS 18, the reasons may be bundled into more than one thing. The report points to a possible connection with iOS 26’s Liquid Glass design language, though it also suggests the gap is unlikely to force Apple into alarm.

Looking ahead, Apple’s next step is already in motion. iOS 27, which includes AI-infused Siri, debuted at WWDC, but it has only entered beta testing. Apple’s message about iOS 27 focuses less on controversial design changes and more on performance: it says app opening speeds will be 30% faster on older iPhones compared with previous releases.

Importantly for upgrade-minded users, the same iPhone models that support iOS 26 can update to iOS 27, including the iPhone 11. So iOS 27 may have more to offer than a redesign—at least in the way Apple is framing it.

Whether that will translate into a higher adoption rate than iOS 26 is still open. But with iOS 26 already climbing from 66% in February to 79% in June. and with iOS 27 promising tangible speed improvements for older devices. the next chapter may come down to how quickly iPhone users decide they can’t afford to wait.

iOS 26 adoption rate iOS 18 adoption Apple App Store data iPhone software update iOS 27 beta AI-infused Siri Liquid Glass design language iOS adoption statistics