Apple is preparing a major behind-the-scenes overhaul with iOS 27.

According to a new report, the update will focus less on flashy design changes and more on cleaning up the operating system’s core — a move that could boost battery life and performance.

According to Bloomberg’s Mark Gurman, Apple’s upcoming iOS 27 update — internally code-named “Rave” — will prioritize refining the operating system’s internals.

Engineers are expected to remove outdated code, rewrite certain existing features, and subtly upgrade built-in apps to enhance overall system performance.

The effort is being compared to what Apple achieved with Mac OS X Snow Leopard, a release widely praised for improving speed and stability rather than introducing major visual changes.

The result of this internal overhaul could be a “snappier, more responsive” operating system, Gurman reports.

While Apple is planning some interface tweaks, users should not expect a dramatic visual redesign like the Liquid Glass overhaul introduced with iOS 26.

Instead, the focus appears to be on system optimization — improving how smoothly apps open, animations run, and processes operate in the background.

Battery life improvements expected

One of the most significant benefits of the cleanup effort may be improved battery life.

Gurman says Apple is working on efficiency upgrades that it hopes will translate into tangible battery gains for users. However, it remains unclear whether Apple will actively market these improvements or allow users to notice the difference organically.

If successful, the changes could make iPhones last longer on a single charge — a key concern for many users.

Preparing for new device categories

The timing of the iOS 27 overhaul is strategic.

Apple is reportedly preparing to launch new device categories in the second half of 2026, including a touchscreen MacBook Pro and its first foldable iPhone.

Ensuring that iOS runs smoothly and efficiently will be critical as Apple expands into more complex hardware designs and form factors.

Beyond performance improvements, Apple is also focusing heavily on artificial intelligence in iOS 27.

The revamped, chatbot-style Siri that Apple announced in June 2024 has faced repeated delays. Some of its anticipated features are now expected to debut in iOS 27 rather than iOS 26, according to Gurman.

Strengthening AI capabilities is said to be one of Apple’s top priorities as competition in the AI-powered smartphone space intensifies.