Macworld Test Finds iPhone Always-On Display Has Minimal Impact on Battery Life

The always-on display has become a familiar feature on Apple devices, but iPhone owners have long wondered whether keeping the screen constantly active drains the battery faster. Macworld set out to answer that question with a small structured experiment, and the results may surprise users who disable the feature out of caution.

According to Macworld, the test used an iPhone 17 running iOS 27 Beta 3 over two weeks. During the first week, the always-on display remained enabled for daily use. In the second week, the screen was set to switch off when not in use. Battery status was recorded at 15-minute intervals each day and sorted into two groups: always-on and always-off. Macworld reports this produced 672 data points per category.

The publication then filtered out rows showing battery levels while the phone was charging, leaving only discharge data, and calculated an hourly discharge rate. Macworld states the iPhone lost an average of 4.27 percent per hour with the always-on display active, compared with 3.75 percent per hour with it off. During the daytime window from 8 a.m. to 11 p.m., the discharge rates were 5.88 percent and 5.37 percent respectively.

Perhaps more important than the raw averages is the statistical picture. Macworld reports the two discharge curves ran almost parallel, and a t-test produced a p-value of 0.3011. Since statistical significance is conventionally set at 0.05 or lower, the outlet concludes that enabling or disabling the always-on display had no significant effect on battery life.

The findings align with what Apple claimed when it introduced the always-on display on the iPhone in 2022, according to Macworld. The company said that when the screen is locked, the refresh rate drops to 1Hz, substantially reducing power draw. Macworld's data supports that explanation in ordinary conditions.

It is worth noting the practical context Macworld describes. The always-on display is not always active even when enabled. It switches off in several situations: when Sleep mode is on, when the iPhone is placed face down, when a paired Apple Watch is not nearby, and when CarPlay is active in a vehicle. These automatic behaviors reduce the time the screen spends in its dimmed, always-on state, which may help explain the modest measured difference.

Macworld also cautions that real-world battery use is influenced by user behavior, cellular signal strength, and outside temperatures, and that these variables can overshadow the effect of the display setting itself. In other words, whether the always-on display is on or off may matter less than how someone uses their phone throughout the day.

Consumers weighing this feature should keep the experimental scope in mind. Macworld tested a single device on a beta version of iOS, over two weeks, with one week assigned to each condition. The sample is small, and the report does not claim to measure every possible usage pattern. The results are most useful as an indication that, in this particular setup, the always-on display was not a major battery drain.

For users who value the always-on display's convenience—seeing the time, notifications, and widgets without waking the phone—Macworld's testing offers a measure of reassurance. The feature appears unlikely to force a significant trade-off in battery endurance under typical conditions. Those who remain concerned can still disable it, but based on this data, the power savings may be smaller than expected.

The original reporting comes from Macworld, which noted the article first appeared on its sister publication Macwelt and was translated and localized from German.