Apple is reportedly preparing a major internal overhaul for iOS 27, with development efforts centered on rewriting core components of the operating system to improve performance and energy efficiency ahead of its expected launch in September 2026.
According to industry reports, the upcoming update will prioritise optimisation rather than headline features, as Apple works to modernise parts of the platform that have accumulated over years of incremental updates.
Rewriting the foundation
The company is said to be rebuilding selected system elements from the ground up while removing legacy code that is no longer necessary. Although specific features affected by the rewrite have not been disclosed, the changes are expected to streamline system operations and reduce background overhead.
In addition to core system work, Apple is reportedly planning performance improvements for certain applications. It remains unclear whether these gains will come solely from the operating system changes or if individual apps such as Safari or Pages will also receive direct updates.
Battery efficiency a key goal
The primary objective of the overhaul is improved efficiency. By making iOS run more smoothly and with fewer resource demands, Apple aims to lower power consumption across devices.
If the changes deliver as expected, iPhone users who upgrade to iOS 27 could see noticeable gains in battery life without any hardware changes.
The focus on efficiency aligns with Apple’s broader strategy of balancing performance with power management as system features — particularly those related to artificial intelligence — become more demanding.
Hardware improvements also expected
Battery life gains in 2026 may also be supported by new hardware. The upcoming iPhone 18 Pro Max is expected to feature improved endurance, while a rumored foldable iPhone could include the largest battery capacity ever used in the lineup.
However, real-world performance will depend heavily on the efficiency of Apple’s next-generation A20 processor, which is expected to power the premium models.
With iOS 27, Apple appears to be shifting its focus to foundational improvements — a move that could deliver tangible benefits in speed, stability, and battery life, even without significant visible changes.
