Modern Android smartphones include a “Smart Network Switch” or “Adaptive Wi-Fi” feature designed to keep you connected to the internet at all times. If you are connected to a Wi-Fi network, but your phone detects that the router’s internet connection is slow, unstable, or completely disconnected, the operating system will automatically and silently switch your phone over to your cellular data connection (4G/5G).
While this ensures your Spotify stream doesn’t buffer, it is a massive problem if you are on a limited, metered data plan. If your home internet goes down while you are downloading a massive 4GB movie, your phone will instantly switch to cellular data and obliterate your entire monthly bandwidth cap without giving you any warning.
To prevent massive phone bills, you must force your Android phone to remain strictly on Wi-Fi, even if the connection is dead.
How to Turn Off Smart Network Switching
This setting is typically found in the Advanced Wi-Fi settings, though the exact name varies by manufacturer.
- Open the Settings app on your Android device.
- Tap on Network & internet (or “Connections” on Samsung devices).
- Tap on Wi-Fi.
- Tap the three vertical dots in the top-right corner (or the Settings gear icon) and select Advanced (or “Intelligent Wi-Fi”).
- Look for a toggle switch labeled Switch to mobile data (Samsung) or Auto switch to mobile network.
- Turn this toggle switch to the Off position.
Your phone will now stubbornly cling to whatever Wi-Fi network you connect to. If your home router loses its connection to the internet, your phone will simply lose internet access, safely protecting your expensive cellular data pool.