Android
Turn Mobile Data On or Off auf Android
Mobile data is the connection your phone uses for the internet once you leave your home Wi-Fi network. It runs through your carrier and counts against the data allowance in your contract, so switching it off when you do not need it protects your plan.
On a phone with two SIM slots, mobile data is tied to whichever SIM you pick as active for data. Toggling the wrong SIM by mistake is the most common reason people think mobile data is on but still see no connection.
To turn mobile data on or off, follow this path:
Tap on Settings ➔ Tap on Network & internet ➔ Tap on SIMs ➔ Choose a SIM card (Dual SIM) ➔ Enable or disable Mobile data
If you only have one SIM, the same screen shows a single toggle for mobile data. Turning it off stops all cellular data use immediately, while calls and texts keep working as normal since those run on the carrier network independently.
Switch mobile data off when you are on an unlimited Wi-Fi connection and want to avoid background apps eating into your plan, or when traveling and you want to prevent roaming charges. Leave it on if you rely on your phone for navigation or messaging apps outside of Wi-Fi range.