Response Time Test

In short Response time is how long a pixel takes to change from one colour to another, and it is what separates a clean moving image from a smeared one. This runs moving patterns at increasing speeds so you can find the point where your panel visibly breaks down, which is a more useful thing to know than a number, because it tells you where the limit is in the content you actually watch. What it cannot do is give you a millisecond figure, and any web page claiming to measure one should be treated with suspicion: real response time is measured with a photodiode and an oscilloscope pointed at the panel, and nothing running inside a browser can see when a pixel finished changing. Two things to check before blaming the panel. Overdrive settings change response dramatically and are usually adjustable in the monitor's own menu. And a slow reading at a high refresh rate sometimes means the display is not actually running at that rate — confirm with the refresh rate test first.