This article explains how to prevent an Android device from automatically connecting to a Wi-Fi network when it's available.
Steps
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Step 1. Launch the Device Settings app
It has a gray gear or wrench icon.
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Step 2. Locate the Wireless and Networks tab
It is displayed at the top of the "Settings" menu.
Depending on the make and model of the device and the version of Android installed, you may need to select the option Connections in the "Settings" menu.
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Step 3. Select the Wi-Fi item listed in the "Wireless and Network" section
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Step 4. Activate the Wi-Fi slider by moving it to the right
It is located in the upper right corner of the screen. A list of all wireless networks in the area where you are will be displayed.
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Step 5. Press and hold the name of the Wi-Fi network you want to delete
The context menu of the selected network will be displayed.
Depending on the make and model of the device and the version of Android installed, you may need to simply tap on the name of the network under consideration, rather than holding it down with your finger
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Step 6. Select the Forget Network, Forget Network or Forget option from the menu that appeared
The device will be disconnected from the indicated network and the corresponding Wi-Fi connection will be deleted from the list of stored ones, preventing the device from automatically connecting when the wireless network is available.