Aim Trainer

Click the targets as fast as you can. Tracks accuracy and reaction time — sharpen your mouse aim.

Pointing accuracy is one of the few areas of interface design with a real predictive law. Fitts's law, from 1954, says the time to hit a target scales with the log of the distance divided by the target's width — which is why a big close button is faster than a small far one, and by how much.

That is also why the standard advice for aim practice is to work on consistency before speed. The law describes a tradeoff curve rather than a fixed limit: you can move faster at the cost of accuracy or vice versa, and training moves the whole curve rather than any single point on it.