It is also not the most accurate method because it may add up additional lag when you have to start and stop the stopwatch.
This method involves a lot of work that include analyzing the frames and then accurately measure the time between them using a stopwatch. The most common way to measure input lag is using a high-speed or normal digital camera and then recording time between the input you have triggered on mouse/keyboard and its effect or action is seen on the monitor screen. In story-based games, role-playing games (RPG) and slow-paced games, input lag does not make that much of a difference, but in fast-paced FPS games (CS:GO, PUBG, Overwatch, etc.), competitive games and esports games, it matters a lot and you should always try to keep the input lag as low as possible because if you have higher input lag, then competitors with lower input lag can have a significant advantage over you as they can make a move faster than you. Input lag is measured in milliseconds (ms), and in some cases, it can also specify in frames.
