Having Wi-Fi turned on drains your battery if you're not using it, but if you're on a wireless network, it's more power-efficient to use Wi-Fi than to use cellular data, so switch to Wi-Fi instead of your mobile network when you can to save your phone's battery life.

Yes, Wi-Fi technically drains your phone battery, but in 2026, it is significantly more battery-efficient than using mobile data (4G or 5G). This is because a cellular connection must "reach out" to towers that may be miles away, requiring much higher transmission power to maintain a stable signal, especially in areas with poor coverage. Conversely, a Wi-Fi router is usually within 100 feet, allowing the phone's radio to operate at a much lower power state. Modern smartphones also utilize "Wi-Fi Scanning" to help with location services, which uses a tiny amount of power even if you aren't actively using the internet. The biggest battery drain occurs when your phone is searching for a signal; if you are in an area with no Wi-Fi, leaving it "on" causes the phone to constantly scan for a network, which is more taxing than if it were connected and idle. Generally, for the best battery life throughout a day, it is recommended to keep Wi-Fi on and connected whenever a trusted network is available, as the energy required to process data over Wi-Fi is nearly nil compared to the aggressive power consumption of a 5G cellular modem.