Glossary
PWM flicker
Pulse-Width Modulation flicker — a brightness-control technique that rapidly cycles the backlight or OLED on and off. At low frequencies, sensitive viewers perceive flicker; eyestrain and headaches can result.
Most modern displays dim by reducing the duty cycle of pulses to LEDs or OLED elements rather than lowering voltage. The display is fully on for part of each cycle and fully off for the rest.
Why some users notice
- OLED phones at low brightness often use PWM in the 240–480 Hz range. Sensitive viewers report eye fatigue and headaches.
- High-frequency PWM (1,920+ Hz) is widely considered imperceptible. Recent flagship OLEDs (OnePlus 12, Honor Magic series, Xiaomi 14 Pro) advertise 2,160 Hz to 4,320 Hz PWM for sensitive users.
- DC dimming lowers voltage instead of cycling. Cleaner for sensitive viewers but harder to implement cleanly on OLED without color shifts.
What to check
- PWM frequency at minimum brightness (the worst case).
- Whether the device offers a DC-dimming or "anti-flicker" toggle.
- Independent measurement (Notebookcheck, DXOMARK) — manufacturers don't always publish PWM specs.
In comparisons
For users sensitive to PWM, this single spec can outweigh peak brightness, refresh rate, and color accuracy combined.
Where this matters
Categories that use pwm flicker
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