Manually closing apps is a common practice among many iPhone users. The belief that clearing multitasking helps save battery is widespread, but Apple has been clarifying for years that the system doesn't work that way. In fact, Forcing the continuous closing of apps can have the opposite effect to what is expected. iOS is designed to automatically manage resources and maintain a balance between performance, energy consumption, and system fluidity.
The company has issued an official explanation. Craig Federighi, senior vice president of software engineering, responded firmly when a user asked him if he closed apps to save battery: “No and no”Former Apple engineers have also reiterated that iOS is designed to keep apps paused and ready to resume quickly. When an app is force-quit, the system loses that ready state and must reload it from scratch the next time it's used.
On a technical level, this has a cost.An app removed from memory forces the processor to perform a work spike when it is reopened. This can consume more energy than simply waking it from sleep. It's a process similar to repeatedly restarting a device instead of letting it rest: it involves more effort and consumes more power.
On the other hand, keeping apps in multitasking doesn't mean they're actively running. In most cases, iOS freezes their activity so they don't use CPU or battery. Only certain functions (like audio playback or GPS usage) continue in the background as needed by the app. If the concern is avoiding automatic updates, the appropriate option is Settings> General> Background updatewhere the user can decide which apps have permission to refresh content.
The only situation in which Apple recommends manually closing an app is when it stops responding or malfunctions. Outside of that case, systematically swiping to close provides no benefits and can harm both performance and autonomy. iOS is designed to handle multitasking without user intervention, and relying on that design is the most efficient way to use the device.