Xiaomi Redmi 9 smartphones are equipped with bright LED-It's a flash that you can use not only for photos, but also as a visual alert for new notifications, which is especially useful in noisy places or when the phone is down. MIUI The option is often hidden or disabled by default – many users do not even know it exists.
In this article, we’ll look at all the ways you can activate a flash to alert Redmi 9 (including Redmi 9A/9C/9T models) by looking at different versions of the firmware, how to enable the feature through system settings, third-party apps, and even through hidden developer commands, and why flash sometimes doesn’t work and how to fix it.
Before you start setting up, make sure your Redmi 9 is updated to the current MIUI version (preferably 13 or 14). In older firmware (e.g. MIUI 12), the path to settings may be different and some features may not be available. Also check that the flash is physically sound: try taking a photo with the flashlight on. If the LED doesn't burn, the problem may be in the hardware.
If you use custom firmware (like LineageOS or Pixel Experience), the configuration algorithm will be different, as we’ll explain in a separate section, and for those who prefer maximum customization, we’ll give instructions on how to activate the flash via ADB (no root rights).
1. Standard method: Configure through “Special features”
The easiest way to include flash notifications is to use built-in MIUI options. This method works on most Xiaomi smartphones, including Redmi 9, Redmi Note 9 and other models based on Android 10/11/12. The main condition is the presence of a standard shell (without deep modification).
Step instructions:
- Open the Settings app (the gear icon on the home screen).
- Scroll down and select the Special Opportunities section.
- Tapping on the item Hearing (in some versions of MIUI it may be called Audio/Visual Alerts).
- Find the option of Notification Flash or Light Indication and activate the switch.
- In additional settings (cog next to the switch) select: 🔦 Flash color (white or color if supported). ⏱️ Duration (short/long/repeated). 📱 Applications (select which notifications to trigger).
Once activated, check the function: ask a friend to send you a message to WhatsApp or Telegram, or use a test notification via the Settings → Notifications → Notification Test. The flash should flash even when the screen is off, but only if the phone is not down screen (in this case, the proximity sensor is triggered).
Flash is flash mode | Phone updated to the latest version of MIUI| No active energy saving modes | Notifications for applications are included in the settings-->
2. Alternative method: flash control applications
If your version of MIUI does not have a built-in light display option (relevant for some regions or custom firmware), you can use third-party utilities. We tested several applications and selected the most reliable ones:
Top.-3 Flash control applications on Redmi 9:
- ⚡ Flash Alerts 2 (paid trial version) – allows you to adjust the color, frequency and duration of the flash, and also adds vibration.
To install and configure the selected application:
- Download the utility from Google Play (links above).
- Activate the switch and adjust the settings: 📌 List of applications (for example, only Viber and SMS). 🎨 Color and intensity (if maintained). 🔄 Repeat (single or cyclic flashing).
Save the settings and test the work.
Flash Notifications|Flash Alerts 2|Light Flow|Built-in settings MIUI|Other-->
⚠️ Note: Some flash management apps may conflict with Xiaomi system optimizers (e.g. Security or Battery Saver).If the flash doesn't work, add the utility to the list of autostart and battery optimization exceptions.
3. Hidden settings: activation through developer mode
For power users who want to get maximum control of the flash, there is a method through the developer mode, which allows you to fine-tune the blinking parameters, but requires caution - incorrect changes can lead to system failures.
How to turn on the developer mode and configure the flash:
- Activate Developer Mode: Go to Settings → About Phone. Tap 7 times on MIUI Version (you will be notified "You are a developer").
Settings
For developers
Symbolic debugging
USB debugging
ADB
- Connect your phone to your PC and execute the command: adb shell settings put global notification_light_pulse 1
- To set the blinking duration (in milliseconds): adb shell settings put global notification_light_pulse_duration 1000
💡
If the flash stopped working after the update MIUI, Try to roll back to the previous firmware version via Fastboot. 4PDA model-themed.
5. Customization for custom firmware (LineageOS, Pixel Experience)
Users who have installed alternative firmware on their Redmi 9 often lack a built-in light display function, in which case you will either need to use third-party applications (see section 2) or edit system files manually.
For AOSP-based firmware (e.g. LineageOS), the following methods are available:
- 📱 Install a Magisk module called FlashLight Notification Enabler – it adds flash support for system-level notifications.
- ⚡ Edit the build.prop file by adding a line: ro.config.notification_light_pulse=1 (Requires Root Rights and Knowledge of Working with ADB file manager, such as Root Explorer).
- 🔧 Use Tasker or Automate to create automatic flashlight rules when you receive notifications.
⚠️ Attention: Editing system files on custom firmware can lead to bootloop or other crashes. Always back up before making changes!
If you’re not sure about your skills, it’s best to limit yourself to third-party apps — they’re safer and don’t require deep system tweaking. For firmware like Pixel Experience, the Pixelify module is also available, which adds features to the original Google Pixel, including advanced notification settings.
6. Battery Optimization: How to Reduce Energy Consumption
Continuous use of flash notifications can increase battery consumption by 5-10% per day (according to XDA Developers tests).To minimize the impact on autonomy, follow these tips:
Ways to save charge:
- 🔋 Turn off the flash for unimportant apps (such as games or newsfeeds).
- ⏳ Reduce the blinking time to 500-800 ms (enough to attract attention).
- 🌙 Use the function only during daytime when vibration or sound may not be noticeable.
- 🔄 Configure repeated blinking no more than 1 time in 2 minutes (so as not to drain the battery in vain).