Apple says 74% of iPhones launched in the last four years and 66% of all iPhones are running iOS 26; 68% of iPhones were running iOS 18 as of Jan. 21, 2025
Context & Ripple Effects
Apple's figures provide an official benchmark after third-party estimates put January iOS 26 usage near 50%, highlighting how measurement method can materially change the adoption picture.
The February reading also serves as a baseline for Apple's later update showing higher iOS 26 penetration by June, indicating that the newer release continued to spread across both recent and older iPhones.
First-order effects
- Developers can treat iOS 26 as the primary deployment target for recent iPhones, while a substantial share of the full installed base still requires support for earlier versions.
- Apple gains a company-reported adoption metric for communicating the reach of iOS 26 to developers and users.
Second-order effects
- App developers and mobile marketers must balance adoption of iOS 26-specific capabilities against compatibility work for the roughly one-third of iPhones not yet on the release.
- The gap between Apple's figures and earlier third-party estimates makes first-party platform data more consequential for planning release support and campaign reach.
Third-order effects
- If updates continue to spread more gradually than prior releases, iPhone software support may remain fragmented for longer, raising the value of backward-compatible app development.
- Adoption reporting itself could become a competitive platform signal: developers will increasingly distinguish between vendor telemetry and external measurement rather than treating either as a complete view.
The trend: iOS 26 is part of a broader shift toward more uneven mobile OS adoption, making installed-base compatibility and trusted measurement more important for the app ecosystem.