There are a lot of different terms thrown around when describing the key action (how the keys respond when engaged) of digital pianos.
In order to better understand which key action you should look for when purchasing a digital piano to best suit your needs, we’ve provided a list of easy to understand definitions for each type of key actions as well as explanations for why certain ones are the best.
Unweighted Key Action
This one is exactly what it would seem to be: there are no weighting mechanisms to any of the keys. This is commonly found on keyboards and less expensive digital pianos, as the spring-loaded keys are much lighter and less expensive to produce.
While unweighted keys help keep the weight and cost down, they are best avoided if you are looking to purchase a digital piano that will give you a realistic playing experience.
Semi-weighted Key Action
While this key action does have weights to better simulate the keys of an acoustic piano, they are not nearly as heavy as they would have to be to fully replicate the feel of playing an acoustic piano.
Semi-weighted key actions can be a decent compromise if portability is extremely important to you, but like unweighted key actions they are usually best avoided.
Hammer Weighted or Fully Weighted Key Actions
The two interchangeable terms refer to key actions that are weighted to the precise level an acoustic piano would be. Weights inside the instrument simulate the sensation of a rising and falling hammer, and there are no springs necessary to lift the keys back up.
If you are wanting to purchase a digital piano that will give you the best possible playing experience, then hammer weighted keys are an absolute necessity.
It may not seem like that significant of a feature, but having a digital piano that correctly replicates the tactile sensation of playing an acoustic piano is a must have if you really want to become good with the instrument.
Graded Key Action
Both semi-weighted key actions and hammer weighted key actions can be graded. What this means is that as you go from the low end of the keyboard to the high end, the weights become lighter, correctly simulating the way an acoustic piano feels since the hammers at the low end of an acoustic piano are much larger and heavier than those at the high end.
No digital piano is capable of perfectly replicating the key action of an acoustic piano, but key actions that are hammer weighted and graded are as close as you will be able to get.
Fortunately, many companies have recognized this and have produced digital pianos at a variety of price ranges that sport key actions that are both graded and hammer weighted.
If you are looking for a digital piano that will provide you with the best and most realistic experience, then it is our recommendation to purchase a piano that describes itself as having a graded, hammer weighted key action.