Wi-Fi Disconnects When Phone Screen Goes Black: How to Fix

Have you noticed that Wi-Fi on my phone turns off immediately after the screen is locked.This is a common problem that interferes with downloads, app updates, and even notifications. The cause could be in the smartphone's settings, router settings, or even the specifics of the mobile operating system. In this article, we'll look into it. all possible reasons — from basic power saving settings to hidden firmware parameters, and we will also provide step-by-step troubleshooting instructions for Android And iOS.

It is important to understand that Automatically turn off Wi-Fi when the screen is off — This isn't always a mistake. Some devices have this feature enabled by default to save battery life. However, if you need the internet to be running all the time (for example, for VoIP calls, cloud backups or remote access), this behavior can and should be adjusted. Below is a detailed analysis, taking into account various scenarios.

1. Checking basic energy saving settings

The first thing to do is disable aggressive power saving, which can forcefully disconnect a Wi-Fi connection. Android And iOS This is done in different ways, but the essence is the same: the system tries to extend battery life by sacrificing background processes.

On Android (For example, Samsung Galaxy, Xiaomi Redmi, Google Pixel):

• 🔋 Go to Settings → Device Care → Battery.
• 🔍 Find the section Power saving mode or Adaptive Battery and turn it off.
• ⚙️ In some firmware (for example, MIUI) there is a separate point Settings → Battery → Power saving settings → Wi-Fi during sleep - set the value "Always".

On iPhone (iOS 15 and later):

• 🔋 Open Settings → Battery.
• 🔄 Disable the option Low Power Mode.
• 📶 Check if the setting is enabled Settings → Wi-Fi → Request Wi-Fi (if any).

If the problem persists after these steps, the default settings aren't the issue. Let's move on to a more in-depth diagnosis.

⚠️ Attention: On some devices Xiaomi And Huawei The Wi-Fi power saving feature may be hidden in the developer menu. To enable it, go to Settings → About phone → MIUI version (or Build number) and tap on it 7 times.

2. Wi-Fi settings in sleep mode (Android)

On Android There's a hidden setting that directly controls Wi-Fi behavior when the screen is off. It's called Wi-Fi in sleep mode (Wi-Fi sleep policy) and can have three meanings:

• 🔄 "Always" — the connection is not broken.
• 🔋 "Only when connected to charging" - battery saving.
• ❌ "Never" — Wi-Fi turns off when blocked.

How to change this setting:

1. Open Settings → Wi-Fi.
2. Click on the three dots (⋮) in the upper right corner and select "Additionally" or Advanced Settings.
3. Find the item Wi-Fi in sleep mode and install "Always".

If there is no such option, it means it is hidden by the manufacturer. In this case, developer menu:

Settings → System → Developer options → Keep data on

Disable Power Saving Mode|Set "Wi-Fi on during sleep" to "Always"|Check Developer Options|Restart your phone-->

3. Router Problems: Why Does It "Reset" the Device?

Sometimes it's not the phone's fault, but router. Many budget routers (for example, TP-Link TL-WR840N, D-Link DIR-300) have a limited pool DHCP addresses or the rental period is too short IPIf the phone is inactive for a long time, the router may "forget" it and give the address to another device.

How to check and fix:

• 🔄 Increase DHCP lease time: Go to your router's control panel (usually 192.168.0.1 or 192.168.1.1), find the section DHCP and set the rental time to at least 24 hours.
• 📡 Disable your router's power saving: In the wireless network settings (Wireless → Advanced) may be an option "Wi-Fi Power Save" - turn it off.
• 🔒 Reserve IP for phone: Tie it up MAC address phone to static IP in the section DHCP Reservation.

⚠️ Attention: If you have a router from a provider (for example, Rostelecom, Beeline, MTS), access to some settings may be restricted. In this case, please contact support and request to disable "Wi-Fi Power Save Mode".

4. Reset network settings and update firmware

If the previous steps did not help, the problem may be in network settings conflict or outdated phone/router firmware. Let's start with the phone:

For Android:

• 🔄 Go to Settings → System → Reset → Reset Wi-Fi, mobile network, and Bluetooth settings.
• 📱 After the reset, reconnect to the network by entering the password again.

For iPhone:

• 🔄 Open Settings → General → Transfer or reset iPhone → Reset → Reset Network Settings.
• 🔐 You will have to re-enter passwords for all saved Wi-Fi networks.

Also check firmware updates:

• 📱 On Android: Settings → System → System Update.
• 🍎 On iPhone: Settings → General → Software Update.

What should I do if Wi-Fi still turns off after a reset?

If resetting doesn't help, try the following:

1. Remove the network from saved (Wi-Fi Settings → Tap on the network → Delete), then reconnect.

2. Check if it is blocking antivirus (For example, Avast, Kaspersky) background activity.

3. Try connecting to a different network (for example, share Wi-Fi from another phone) - if the problem persists, the phone is to blame; if it disappears, the router is to blame.

5. Problems with specific phone models

Some devices have unique bugs, related to Wi-Fi disconnection. Here are the most common cases:

Samsung Galaxy (One UI):

• 🔧 Turn on Always scan networks V Settings → Connections → Wi-Fi → ⋮ → Advanced features → Always scan.
• 🔄 Turn it off Smart Wi-Fi in the same menu.

Xiaomi/Redmi/POCO (MIUI):

• 🔋 In Settings → Battery → App Selection find "Wi-Fi" and install "No Limits".
• 📡 In Settings → Wi-Fi → Advanced → Connect to Wi-Fi during sleep select "Always".

Google Pixel:

• 🔧 Turn on Mobile Internet and Wi-Fi are always on. V Settings → Network & Internet → Internet → ⚙️ → Mobile data and Wi-Fi always on.

iPhone (iOS):

• 🔄 Turn it off Low data consumption for Wi-Fi network: Settings → Wi-Fi → ⓘ Near network → Low data usage.

6. Problems with IPv6, DNS and other network protocols

Less often, but accurately: Incorrect IPv6 or DNS settings may lead to connection interruptions. For example, if the router supports IPv6, but the phone does not (or vice versa), the connection may be interrupted when switching to sleep mode.

How to check:

1. Open it on your phone Settings → Wi-Fi → ⚙️ Near your network → IP settings.
2. Try specifying it manually DNS (For example, 8.8.8.8 And 8.8.4.4 for Google DNS).
3. If there is an option "IPv6", try disabling it.

On the router:

• 🔧 Turn it off IPv6 V Network → LAN or WAN (if you don't use it).
• 🔄 Install DNS from Google or Cloudflare (1.1.1.1).

⚠️ Attention: If your provider requires IPv6 for work (for example, for IPTV), do not disable it completely. Instead, try setting a static IPv4.

7. Hardware problems and radical measures

If none of the methods helped, perhaps the problem lies in:

• 📱 The phone's Wi-Fi module is faulty (especially after falls or exposure to moisture).
• 🔌 Poor connection of the router antenna (if the problem occurs on all devices).
• 🔋 Worn out battery, which forcibly turns off modules to save power.

What to do:

• 🔧 Test your phone on a different network (for example, in a cafe or with friends).
• 📡 Connect the router to a different power source (perhaps the power supply does not provide the required voltage).
• 🔄 Perform a full reset of your phone (after saving the data!).

Critical point: if Wi-Fi turns off only on a specific frequency (2.4 GHz or 5 GHz), try manually setting the channel on the router (for example, 6 or 11 for 2.4 GHz) and disabling automatic selection.

FAQ: Frequently Asked Questions

Why does Wi-Fi only turn off at night?

Most likely you have it enabled night power saving mode or the router is configured to turn off Wi-Fi on a schedule (function Wi-Fi Schedule). Check the router settings in the section Wireless → Schedule.

My iPhone's Wi-Fi disconnects after 5 minutes of being blocked. How do I fix it?

On iPhone This is related to the function Low data consumptionDisable it for your network: Settings → Wi-Fi → ⓘ Near network → Low data usage. Also check if the mode is turned on Low Power Mode.

After updating my Android device, Wi-Fi stopped working in sleep mode. What should I do?

This is a known issue with some firmware (eg. MIUI 14 or One UI 5.0). Try:

1. Roll back to the previous version of the software (if possible).
2. Install custom recovery (For example, TWRP) and flash the module Wi-Fi Fix.
3. Please contact the manufacturer's support service with your model and firmware version.

Could a virus be the cause of Wi-Fi disconnection?

Theoretically, yes, but extremely unlikely. Some malicious apps can block network activity, but this usually manifests itself in other ways (advertising, redirects to websites). To check:

• Install Malwarebytes or Dr.Web and scan the device.
• Check the list of installed applications for suspicious ones.
• Start your phone in safe mode (on Android: press and hold the power button → "Safe mode").

How to check if the router is at fault?

Connect another phone or laptop to the same network. If the Wi-Fi doesn't disconnect, the problem is with your phone. If it disconnects, the router is to blame. Also try:

• Connect to the router via cable (if there is a port) LAN).
• Test the router with a different firmware (for example, OpenWRT or DD-WRT).