Why Xiaomi is losing Internet speed – all the reasons and ways to eliminate

Have you noticed that Xiaomi is slowing down when loading pages, video is hanging up and messengers are sending messages with a delay? The problem of falling Internet speed on Xiaomi devices (including Redmi, POCO and Black Shark) is more common than it seems, the reasons are rooted in both hardware limitations and the features of the MIUI firmware - even on flagships like Xiaomi 14 Ultra or Redmi Note 13 Pro+.

In this article, we’ll look at 10 key causes of speed drops, from overheating to hidden power saving settings that MIUI automatically activates at a charge level below 20%, limiting background traffic. You’ll get not only diagnostics, but also step-by-step instructions with illustrations (for Android 12-14 models), as well as a table comparing speeds before and after optimization.

Importantly, if the problem only manifests itself in certain applications (like YouTube or Telegram), first check their settings — sometimes it's not the phone that's the fault, but the servers of the service itself. But if lags are everywhere, read on.

1. MIUI Limitations: Hidden Energy Saving Settings

MIUI is known for aggressively optimizing background traffic, and even on top-end models like the Xiaomi 13T Pro, the system can artificially limit Internet speed if:

• 🔋 Battery level below 15-20% (overpower saving mode is turned on»).
• 📱 The phone has not been rebooted for a long time (cached processes accumulate).
• 🔄 Roaming Data Mode is enabled (even if you are not roaming!).
• 🚫 App added to the list of “Limited” in battery settings.

To check and disable these restrictions:

1. Go to Settings → Battery → Battery Mode.
2. Select the Performance profile (if available).
3. Open Settings → Apps → App Management, find a problem app (like Chrome) and turn off the “Background Limit” option.

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If your model does not have the option “Battery Mode”, try to enter the “energy saving” request in the search for settings – sometimes the option is hidden in the submenu.

Some firmware (e.g. MIUI 14 for Redmi Note 12) has a hidden feature called “Intelligent Traffic Distribution” that prioritizes system processes over user ones. It disables via Settings → Special Features → Developer Settings → Network (if there is no item, then your model does not have one).

2. CPU overheating: why speed drops when loaded

Overheating is one of the most common reasons for the decline in Internet speed on Xiaomi, where at chipset temperatures above 45-50°C, the system automatically trottlits (limits) performance, including data speeds, both mobile Internet (4G/5G) and Wi-Fi.

How to check the temperature:

• 📊 Install the app AIDA64 or CPU Monitor.
• 🔥 Look at the temperature of the processor (Snapdragon/Mediatek) modem.
• 📶 If the temperature is above 50°C when simply loading a page is a critical value.

Decisions:

1. Remove the case – even thin silicone covers can block the heat sink.
2. Close the background applications (especially games and video editors).
3. Turn it off. 5G, If not used: Settings → SIM-maps and mobile networks → Type of network → 4G.
4. Use a cooling stand (relevant to Black Shark or POCO F5) gamers.

On some models (for example, Xiaomi 12S Ultra) overheating of the modem can be associated with a defect in the antenna module. If after 10-15 minutes of using the mobile Internet, the speed drops to 1-2 Mbps, and the temperature of the modem exceeds 60 ° C, this is an occasion to contact the service center.

3.Problems with SIM-card-carrier

If the internet speed drops only on mobile (and Wi-Fi works fine), it may be the fault of:

• 📶 Operator – tariff restrictions, overloading of the base station.
• 🔄 SIM-card – physical wear, improper pruning under nano-SIM.
• 📡 Phone antenna – damage after falling or getting moisture.
• 🔄 Network mode - forced use 3G instead 4G/5G.

Diagnosis:

1. Check the speed on another device with the same SIM-If it's slow, too, the operator has a problem.
2. Call the operator and request a reset of the service profile (sometimes helps with 2G sticking).
3. Put another one in. SIM-Map in your Xiaomi – if the speed recovers, replace the old one.

On models with Dual SIM (For example, Xiaomi 13 Lite speed can drop due to a conflict of slots. SIM-slot-card SIM1 — Sometimes it solves the problem.

4. Misconfigured Wi-Fi settings: from channel to DNS

If the speed drops only on Wi-Fi, the problem may lie in:

• 📶 Overloaded router channel (especially at 2.4 GHz).
• 🔒 Outdated standard (e.g, 802.11n instead 802.11ac/ax).
• 🔄 Incorrect. DNS (For example, the service providers instead of Google DNS or Cloudflare).
• 🛡️ VPN or firewall that blocks traffic.

Optimizing Wi-Fi on Xiaomi:

1. Go to Settings → Wi-Fi → Additional and turn on Wi-Fi 6 (if supported by a router).
2. Change DNS: Select Static IP in your network settings and select DNS 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google).
3. Turn off Wi-Fi Smart Switch (can drop the network at the slightest interference).

Make sure the router supports 5GHz

Disable VPN (if enabled)

Reboot the router and phone

Check the speed on another device

Update router firmware-->

Some MIUI firmware has a bug: the phone forgets the Wi-Fi password after the upgrade and connects to the network, but without Internet access, so the solution is to delete the network and connect again.

5.Outdated firmware or MIUI bugs

MIUI updates often bring not only new features, but also network bugs. For example, MIUI 14.0.4 for the Xiaomi 12 Pro had a bug that caused 5G speeds to drop to 10 Mbps after 5 minutes of use. And MIUI 13 for the POCO X3 Pro had problems with Wi-Fi 6.

How to check and correct:

1. Update the firmware: Settings → About the phone → System update.
2. If the speed has dropped after the update, try to roll back to the previous version (instruction below).
3. Check forums (such as 4PDA or XDA Developers) for known bugs for your model.

For firmware rollback:

1. Download the desired version of Fastboot-ROM from the official Xiaomi website.
2. Use the Mi Flash Tool for firmware (instruction: xiaomi.eu).

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Before rolling back the firmware, back up your data via Settings → Additional → Backup and Reset. The rollback erases all the data on the phone!

On POCO and Redmi with global firmware, switching to a regional version of MIUI (e.g. from Global to EEA) sometimes helps, but this is done through the Mi Unlock Tool, but requires unlocking the bootloader.

Hardware problems: antenna, modem, battery

If the software methods did not help, the reason may be iron:

To check the antenna:

1. Enter the code ##4636### in the engineering menu.
2. Select Phone Information and watch Network Signal.
3. If the signal level <-100 dBm at full scale, the antenna is faulty.

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On models with a metal body (for example, Xiaomi Mi 11), antennas are located on the sides. Do not cover them with your fingers when holding the phone - this degrades the signal.

If the phone falls or comes into contact with water, even after a year, there may be hidden damage, such as corrosion on the board, which causes the modem to work unstable, in which case only repairs will help.

7. Background applications and viruses

Some apps (especially Chinese ones) can devour traffic in the background, leaving you with crumbs of speed.

• 📱 Clean Master, DU Battery Saver – known for aggressive advertising.
• 🎮 Free Fire, PUBG Mobile – can download updates in the background.
• 📊 MIUI Analytics – sends data to Xiaomi (you can disable it).
• 🔍 Fake “optimizers” from unknown sources.

How to clear the background:

1. Open Settings → Applications → Application Management.
2. Sort by Traffic Use.
3. Limit background activity for suspicious applications.
4. Install NetGuard or GlassWire to monitor traffic.

To check for viruses:

1. Download Malwarebytes or Dr.Web Light.
2. Scan the system (especially /sdcard/Download and /data/app).
3. Remove the threats and reboot the phone.

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MIUI has built-in antivirus (Security → Scanning) but it often skips adware. Use third-party solutions for deep validation.

If the speed hasn’t recovered after removing suspicious apps, try resetting to factory settings (but back up first!).

FAQ: Frequent questions about the speed of the Internet on Xiaomi