If your Wi-Fi works normally while you are using your phone but disconnects as soon as the screen turns off, you are not imagining it. This is a common issue, and in most cases it does not mean your phone or Wi-Fi network is broken. Usually, a background setting or power related behavior causes the connection to drop when the phone becomes idle.
The good news is that this problem is often easy to fix once you know where to look.
This issue is a more specific version of general Wi-Fi disconnection problems that can happen for different reasons.
Reason 1: Power Saving Mode Is Limiting Network Activity
Many phones reduce background activity to save battery when the screen turns off. When this happens, Wi-Fi connectivity may be limited or paused without any visible warning.
This often happens quietly, because the phone does not show any clear notification.
What to do:
- Turn off power saving mode temporarily
- Lock the screen and wait a few minutes
- Check whether Wi-Fi stays connected
If the connection remains stable, power saving mode was the cause.
Reason 2: Battery Optimization Is Restricting Wi-Fi in the Background
Some phones apply aggressive battery optimization rules to system services when the device is idle. These restrictions can affect network connectivity and cause Wi-Fi to disconnect after the screen turns off.
You may notice this if Wi-Fi works perfectly while the screen is on but disconnects shortly after the phone becomes inactive.
What to do:
- Open battery or optimization settings on your phone
- Look for background restrictions or optimized system services
- Allow normal background activity for network related features
After making changes, lock the screen and test the connection again.
Reason 3: The Phone Switches to Mobile Data When Idle
When the screen turns off, some phones automatically switch between Wi-Fi and mobile data to maintain what they think is a stronger connection. This switching can cause Wi-Fi to disconnect repeatedly.
In some cases, this behavior can also look like a connection issue where the phone appears connected but data does not flow normally.
What to do:
- Turn off mobile data temporarily
- Connect to Wi-Fi only
- Lock the screen and observe the connection
If Wi-Fi stays connected without mobile data enabled, automatic network switching is likely the cause.
Reason 4: Router Behavior Causes Idle Disconnections
In some cases, the router disconnects inactive devices to manage network load or save resources. When your phone screen turns off, the router may treat the device as inactive.
What to do:
- Restart your router and allow it to fully reconnect
- Check router settings related to idle devices or power management
- Test Wi-Fi again after the restart
If the issue improves, the disconnections were caused by network side behavior.
Reason 5: Saved Wi-Fi Network Settings Have Become Unstable
Over time, saved Wi-Fi configurations on your phone can become outdated or inconsistent. This can lead to disconnections when the phone switches between active and idle states.
What to do:
- Open Wi-Fi settings on your phone
- Forget the affected Wi-Fi network
- Reconnect by entering the password again
- Restart your phone once
This refreshes the connection and often resolves screen off disconnection issues.
Quick Checklist
- Turn off power saving mode temporarily
- Review battery optimization settings
- Disable mobile data and test Wi-Fi only
- Restart the router
- Forget and reconnect to the Wi-Fi network
Final Thoughts
If Wi-Fi disconnects only when your phone screen turns off, it usually points to a background setting rather than a hardware problem. Power saving features, battery optimization rules, automatic network switching, or router behavior are the most common causes. These issues are normal and fixable in most cases. If the problem continues across different Wi-Fi networks and devices, it may be time to check for deeper software issues or contact your device manufacturer.