What is PWM dimming?

PWM (Pulse Width Modulation) dimming is a technique some screens use to lower brightness. Instead of reducing the actual light output, the screen switches the backlight on and off very quickly. When the light stays on longer and off for a shorter time, the screen looks brighter, and vice versa. Your eyes usually can't see this flicker because it's so fast, but it's still happening.

In daily use, most people won't notice anything. However, some users—especially when reading at night or using the phone for long periods—may get headaches, eye strain, or discomfort. This tends to be worse at low brightness levels, where the flicker becomes slower and more noticeable to sensitive eyes. That's why some people look for phones that use other methods, like DC dimming or high-frequency PWM.

When buying, you don't need to understand complex technical numbers, but it helps to know that higher frequencies (like 1920 Hz or more) are usually more comfortable for the eyes than lower ones (like 240 Hz or less). Some phones also offer a "DC dimming" or "flicker reduction" option in the settings. If you're sensitive to light or use your phone a lot in the dark, try the phone yourself or look for reviews that mention screen comfort. Also remember that screen refresh rate (60, 90, or 120 Hz) is different from PWM dimming—both relate to the screen, but each has its own effect.