What Is Flicker-Free Technology And PWM?

Flicker-Free Technology ensures a comfortable viewing experience by eliminating screen flickering (PWM) for good. Here's why you want it.

Answer:

Flicker-Free Technology ensures a comfortable viewing experience by preventing screen flickering as a means of reducing the monitor’s brightness.

Flicker-Free Technology (also referred to as Flicker-Less, Anti-Flicker and similar) indicates that a monitor doesn’t use PWM (Pulse-Width Modulation) to regulate the display’s brightness.

The PWM method includes turning the backlight on and off rapidly, and even though the flickering frequency is invisible to the human eye, it can still cause eye strain and headaches to those sensitive to it after prolonged use.

Luckily, most modern monitors are flicker-free, meaning that they use DC (Direct Current) modulation to regulate the brightness instead, which provides a constant stream of light at any brightness level.

Now, keep in mind that some monitors may be advertised as ‘Flicker-Free’ but actually are not, such as the Samsung U32J590.

Displays that use PWM introduce flicker only at lower brightness settings (usually lower than 20% – 30%, sometimes even below ~50%).

This is still an issue for those who prefer lower brightness levels, whether because they work in dim-lit environments or because their monitor’s luminance is simply too strong, even below 50%.

PWM vs Flicker free Comparison

On the other hand, some completely flicker-free displays might not include that information in the monitor’s spec sheet.

In our monitor reviews, we always mention whether a display uses PWM to regulate brightness. While most new monitors use DC modulation, there are some exceptions.

OLED monitors and TVs don’t have a backlight, but they exhibit minor dips in brightness that match the screen’s refresh rate. However, these slight brightness oscillations aren’t visible to the human eye and won’t cause any issues to most users.

Other flickering-like artifacts on displays can be caused by FRC (temporal dithering) on 6-bit displays, VRR brightness flickering (mainly on OLED and VA panels) and slow pixel response time speed in fast-moving dark scenes (mainly on VA panels).

Visit our best gaming monitors and best monitors for office work buying guides to check out the best flicker-free displays available.

To test whether your monitor uses PWM, go here. You can also test this by pointing your phone’s camera to the screen, if the camera shows the screen with scrolling horizontal lines, your monitor is flickering, even if you don’t see it with your eyes.

Even if your display uses PWM at low brightness, there is something you can do to prevent it.

You can download a third-party application that will decrease the brightness by altering your graphics card’s white point value, while allowing the monitor’s brightness to be set at 100%, thus avoiding PWM. This will affect color accuracy though.

Other things that can affect your viewing comfort include proper anti-glare screen treatment and Low Blue Light Technology.

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Rob Shafer

Rob is a software engineer with a Bachelor’s degree from the University of Denver. He now works full-time managing DisplayNinja while coding his own projects on the side.