Why Xiaomi Redmi 9 is slowing down and how to fix it: the full guide 2026

Your Xiaomi Redmi 9 is getting stuck, apps are opening for a long time and animation is twitching? These are typical slowdown symptoms experienced by budget smartphone owners after 1-2 years of use. The reasons can lie in a contaminated system (cache, junk files) and hardware limitations - only 3/4 GB of RAM and the Helio G80 processor are not eternal. But don't rush to buy a new phone: in 90% of cases, the problem can be solved software.

In this article, we will discuss all possible causes of brakes, from the banal lack of memory to hidden errors in MIUI firmware, as well as give step-by-step instructions for optimization. Particular attention will be paid to the unique features of Redmi 9, which are not found in other Xiaomi models: for example, how to properly manage background processes in MIUI 12/13 or why this model is so acutely responsive to overheating. All tips tested on current versions of the software (2026) and do not require root rights.

1.Diagnosis: How to understand why the Redmi 9 is slowing down

Before you start treatment, you need to make a diagnosis, the brakes on Redmi 9 can manifest in different ways:

• 🐢 Lags when opening applications - a long appearance of icons, hanging on 2-5 seconds.
• 🔄 Twitching animations – transitions between screens are not smooth, but “step-by-step".
• 🔥 Overheating and a sharp drop in productivity - after 10-15 minutes of games or video smartphone starts to "dumb".
• 📉 Spontaneous reboots – usually associated with memory shortages or firmware errors.

To identify the root of the problem, follow these steps:

1. Check CPU and RAM boot: Open Settings → About Phone → System Status. Tap 5 times on MIUI to activate the hidden test menu. Select CPU - if the CPU load is constantly above 70% without active tasks, the software is to blame.

memory monitor

Settings → Applications → Application Management → Active

You can see what programs eat the RAM. Norm for Redmi 9: 1.5-2 GB of free RAM of 3-4 GB.

⚠️ Note: If you see com.miui.analytics or com.xiaomi.midrop in the list of active applications, these are system services. MIUI, They can't be turned off. Forced to stop them will cause disruption!

2. Cleaning the system: remove garbage and cache

The first thing you need to do is to free up space in memory and clear temporary files. On Redmi 9, with its modest 64/128GB of storage, garbage accumulates especially quickly.

• 🧹 Cleaning the application cache: Settings → Annexes → Application management → [Select the application] → Warehouse → Start with the most “gluttonous”: Facebook, Instagram, YouTube, MIUI Launcher.
• 🗑️ Remove unnecessary files: Use the built-in Cleanup app (icon with broomstick).In the Deep Cleanup section, it will find up to 1-3 GB of garbage: remnants of remote programs, duplicate photos, temporary update files.
• 📁 Transfer of data to SD-Redmi 9 supports memory cards up to 512 GB. Transfer photos, videos and music to them through Files → Categories → Images/Video → Select → Move it.

Important: Don't cache system applications like com.android.systemui or com.miui.home, which will cause the interface to crash.

Settings → Battery and Performance → Optimization

⚠️ Warning: If the app crashes after clearing the cache (like WhatsApp or Viber), just restart your phone.

3. MIUI firmware optimization: hidden settings

MIUI on Redmi 9 has a lot of hidden features that you can use to speed up, many of which are undocumented but are actively discussed on the 4PDA and Xiaomi Community forums.

• ⚡ Disable animation: Activate developer mode (7 taps MIUI In Settings → On the phone), then: Settings → Additionally. → For developers → Scale of window/transition animation = It'll speed up the opening of applications to 20-30%.
• 🔄 Background Process Limiting: In the same developer menu, find the Background Process Limit and set a Process Maximum 2.This will reduce RAM consumption, but some notifications may come with a delay.
• 🛠️ Reset graphics settings: If you play games but they slow down, reset the graphics settings: Settings → Special facilities → Graphic settings → Reset This Will Return Factory Rendering Options That Are Optimized for Helio G80.

Exclusive for Redmi 9: This model has a hidden Game Turbo feature that automatically optimizes performance in games.

Settings → Special features → Game Turbo Mode → On.

After activation, a gamepad icon will appear in the notification panel - tap on it during the game to enable acceleration.

4. Update and Firmware Reflash: When It Helps

If your Redmi 9 runs on MIUI 12 or older, there's a high probability that the brakes are related to outdated firmware. Xiaomi regularly releases patches that fix performance errors, but they don't always install automatically.

• 🔄 Checking for updates: Settings → The phone. → System Update If Update is available MIUI 14 (Android 12) — install. It contains optimizations specifically for Helio. G80.
• 📥 Manual installation of firmware: If OTA-Update does not come, download the full package from the official website: https://new.c.mi.com/global/miuidownload/index Choose a Redmi model 9 (garden) and Stable version. Install via System Update → Threefold → Select a firmware file.

Important: When you're manually firmware, don't reset (Wipe Data option) unless you want to lose files.

⚠️ Warning: If after the update the phone began to brake even more, reset the cache (not data!): → Hold the Power. + Vol Up → Choose the Wipe Cache → Reboot This Will Delete Temporary Update Files That May Conflict With The System.

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Before upgrading, connect your phone to charge and make sure the battery is at least 50% charged. Interrupting the firmware process can cause the device to "brick" (completely inoperable).

5. Hardware causes: overheating and battery wear

If the software methods didn't work, the problem could be in hardware. Redmi 9 is known for two hardware weaknesses:

1. CPU overheating: At temperatures above 60°C, the Helio G80 automatically reduces the frequency (trottling), which causes lags. Check the temperature through the AIDA64 app (Sensors section). Normal: up to 45°C in plain, up to 65°C under load.
2. Battery wear: After 300-500 charging cycles, battery capacity drops and the phone starts to "dull" at a charge level below 20%. Check wear in AIDA64 (Battery section). If the capacity is less than 80% of the factory (5020 mAh), it's time to change the battery.

How to deal with overheating:

• 🧊 Remove the cover - it blocks the heat sink.
• 🔌 Do not play while charging (especially fast on the game). 18W).
• 🔄 Clean the radiator of dust (neatly blow the speaker hole with compressed air).
• 📉 Limit it. FPS play-off 30-40 via graphics settings.

Symptoms of a "dying" battery:

• The phone turns off at 10-15% charge.
• Charging jumps (for example, from 30% immediately to 50%).
• At low charge, strong lags appear.

⚠️ Warning: If the battery is swelling (see above the raised screen), immediately turn off the phone and take it to the service!

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Replacement of the battery with Redmi 9 cost 1500-2500 ruble (2026 The original battery has an articular MBJ4067 — Check it when buying to avoid counterfeiting.

Radical measures: dumping and custom firmware

If nothing has worked, there are two extreme methods:

1. Hard Reset: Delete all data, but return the phone to factory status. Do only after backup! Settings → About phone → Reset → Erase all data After reset, the phone will be like new — no lags, but no files.
2. Install custom firmware: For advanced users. Popular options for Redmi 9: Pixel Experience (pure Android without MIUI), LineageOS (stable, but without Google services by default), Xiaomi.EU (MIUI without Chinese software).

Requires unlocking of the loader

Warning: Castom firmware may:

• 🚫 Deprive warranty (unless the bootloader is officially unlocked).
• 🔌 Breaking the job NFC or cameras (check reviews on the 4PDA).
• 🔄 Requires manual updates (no) OTA).

If you decide to cast, follow only the official guides with XDA Developers or 4PDA. For Redmi 9 (codenamed garden), the current instructions are in the topic:

https://4pda.to/forum/index.php?showtopic=963422

7. Alternative solutions: if nothing has worked

If Redmi 9 continues to brake despite all efforts, consider these options:

• 📱 Use lighter versions of apps: Facebook Lite instead of regular Facebook; YouTube Go instead of standard YouTube; Twitter Lite (weighs 10 times less than the original).
• ☁️ Move the applications to SD-Map: Not all programs support this feature, but those that do will relieve internal memory: → Annexes → [Select the application] → Warehouse → Change. → SD-map
• 🔧 Turn off auto-update apps: Play Store → Settings → Auto-update of applications → Never This Will Prevent Background Downloading of Updates That Can Slow Down the Phone.

Last tip: If your phone is used for simple tasks (calls, instant messengers, photos), try disabling all unnecessary Google services:

Settings → Google Accounts → Account Management → Synchronization → Disable unnecessary items

This will reduce background activity and save battery power.

FAQ: Frequent questions about Redmi 9 brakes