Have you ever noticed that after a long time with a Xiaomi smartphone, the eyes start to get tired and the screen seems to tremble? PWM (pulse-latitudinal modulation) - a technology that manufacturers are actively using to adjust the brightness of the screen - can be the culprit, in this article we will discuss what PWM is in Xiaomi smartphones, why it causes controversy among users and how to minimize its harmful effects.
PWM technology has long been used in electronics, but in the context of smartphones, it has become a myth, some argue that PWM harms vision and causes headaches, others consider it a harmless engineering solution, we analyze the way PWM works, compare Xiaomi models by flicker level, and give practical recommendations from screen settings to choosing protected models.
What is PWM and why it is needed in smartphones
PWM (pulse-latitudinal modulation. PWM — Pulse-Width Modulation is a method of controlling the brightness of the screen by quickly turning on and off the backlights, instead of smoothly changing the intensity of light (as in the case of a light-based lighting system). OLED-True-tone displays, the screen flashes at a high frequency, creating the illusion of uniform glow.
Why did manufacturers choose this method?
- 💰 Cheap: PWM regulation is cheaper than alternative methods (e.g, DC dimming).
- 🔋 Energy efficiency: It saves battery life, especially on AMOLED-screen.
- 📱 Compact: No additional hardware components required, which is important for thin smartphone cases.
But PWM has the flip side: screen flickering below 200 Hz can cause eye fatigue, headaches, and even migraine attacks in sensitive users, especially when brightness is low, which is when the pulses get longer and the pauses between them are shorter.
How PWIM works in Xiaomi smartphones: technical details
In smartphones Xiaomi PWM is used mainly in models with AMOLED-screens (e.g. Redmi) K50 Pro, Xiaomi 13 Ultra, POCO F5). In devices with IPS-displays (for example, Redmi Note 12) brightness is regulated differently - due to a change in voltage on LEDs (DC dimming), which eliminates flickering.
Key parameters of PWM in Xiaomi:
- 🔄 Frequency of flickering: Measured in hertz (Hz). The higher the value, the less noticeable the flicker. The optimal threshold is 200 Hz and above.
- 📉 Depth of modulation: Determines how much pulse duration changes when brightness changes. In cheap models, it can be aggressive.
- 👁️ Eye perception: At a frequency below 100 Hz, flickering is noticeable to most users, below 50 Hz - causes discomfort.
Interesting fact: Xiaomi’s flagship models (such as the Xiaomi 14 Pro) use a hybrid system – PWM at high brightnesses and DC dimming at low brightnesses – a trade-off between energy efficiency and eye comfort.
How to Measure the Frequency of PWM by Yourself
Whether PWM is harmful to health: myths and facts
The dangers of PWM are being debated in the medical and technical communities, and let's look at what's been confirmed by research and what's just speculation.
Proven risks:
- 👓 Eye fatigue: Prolonged exposure to flickering below 100 Hz leads to asthenopia (visual fatigue).
- 🤕 Headaches: In 10-15% of users, low-frequency PWM provokes migraines (Journal of Neurology, 2018 study).
- 😵 Epileptic seizures: In rare cases, flickering can trigger photosensitive epilepsy (especially in children).
Unproven or exaggerated risks:
- 🧠 "PWIM damages vision: No evidence it leads to nearsightedness or other serious diseases.
- 💀 "Flickering causes cancer": It's a myth. PWM is not ionizing radiation.
- 😴 "PWM disrupts sleep: It may indirectly affect eye fatigue, but not directly.
⚠️ Attention: If you are at risk (migraines, epilepsy, hypersensitivity to light), avoid smartphones with a PWM frequency below 200 Hz. In extreme cases, flickering can provoke an attack.
Comparison of Xiaomi models by PWM level: table 2026
Not all Xiaomi smartphones are equally harmful to the eyes. We collected data on the frequency of PWM in popular models (measurements were made at 50% brightness):
| Model | Screen type | PWM frequency (Hz) | Level of risk |
|---|---|---|---|
| Xiaomi 14 Ultra | AMOLED, 2K | 480 | ✅ Safe. |
| Redmi K70 Pro | AMOLED, FHD+ | 360 | ✅ Safe. |
| POCO X6 Pro | AMOLED, 1.5K | 240 | ⚠️ Average risk |
| Redmi Note 13 Pro+ | AMOLED, FHD+ | 210 | ⚠️ Average risk |
| Redmi 12C | IPS LCD, HD+ | - (NO SWIM) | ✅ Safe. |
Note: Budget models (e.g. Redmi 12 Series) are often used in the same way. IPS-It's a PWM-free display, which makes it safer for long-term use, but it has lower contrast and higher power consumption.
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Xiaomi flagship models (series) 13/14, K60/K70) high-frequency PWM (360–480 Hz, which is safe for most users.Budgetary AMOLED-display (POCO, Redmi Notes may have a frequency lower than 250 Hz is a potential risk for sensitive people.
How to reduce the harm of PWM: 7 practical tips
If your Xiaomi smartphone uses PWM, but you do not want to change the device, use these recommendations:
Increase the brightness of the screen to 70-80%|Enable a dark theme in the settings|Use a blue light filter (Night Mode)|Reduce the time of continuous work|Choose a model with DC Dimming (if you buy a new one)|Install a flicker control app (e.g. f.lux)|Take breaks every 20-30 minutes-->
1. Brightness adjustment
The flicker is more pronounced when the brightness is low. Try to increase it to 60-80% or use adaptive brightness (Settings → Display → Adaptive Brightness). Some models (for example, Xiaomi 13T) have DC dimming mode — turn it on in Settings → Display → Additional.
2 Dark theme and filters
Black backgrounds reduce eye strain, turn on a dark theme (Settings → Display → Dark theme) and activate a blue light filter (Settings → Display → Reading Mode) to reduce overall fatigue, even if PWM remains.
3. Software solutions
Apps like f.lux or Night Shift can smooth out flickering by correcting color temperature, but they don't eliminate PWM completely, they only mask its effects.
⚠️ Attention: In some firmware MIUI regime DC Dimming may not be available or may not work properly. Check for it in a particular model review before buying.
Alternatives to PWM: what technologies are used by competitors
Xiaomi is not the only manufacturer to use PWM, but some brands offer alternative solutions:
- 📱 Samsung: In flagships (for example, Galaxy) S23 Ultra is used LTPO OLED with dynamic refresh rate and minimal flickering.
- 🍎 Apple: iPhone 15 Pro used ProMotion with support DC dimming at all levels of brightness.
- 🤖 Google: Pixel 8 Pro is equipped with Actua Display with a frequency of PWM 1000 Hz (almost imperceptibly).
Interestingly, even within Xiaomi’s lineup, there are differences: Black Shark, for example, uses screens with a PWM frequency of 1000+Hz to avoid eye fatigue during long gaming sessions.
If eye comfort is critical, look for models with TÜV Low Blue Light or SGS Eye Care certification, which pass additional safety tests.
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When choosing a new smartphone, check the frequency of PWM in reviews on GSMArena or NotebookCheck. The optimal score is from 360 Hz and above. If the frequency is below 200 Hz, it is better to consider alternatives with IPS or DC dimming.
The future of PWM: what awaits technology in smartphones Xiaomi
Manufacturers are gradually abandoning low-frequency PWM in favor of safer solutions, and in 2026 Xiaomi announced several innovations:
- 🔬 LTPO 4.0: New version of technology that allows dynamically adjusting the frequency of PWM depending on the content (up to 1-120 Hz).
- 🌿 Eco-friendly displays: Xiaomi 14 Series uses Eco-OLED with reduced flickering and power consumption.
- 🧠 Adaptive DC dimming: AI algorithms analyze user behavior and automatically switch between PWM and PWM. DC dimming.
By 2026, most Xiaomi flagships are expected to have screens with a PWM of 500+Hz or no flicker, but the low-cost technology will remain in the low-end segment for a long time to come.