 The potassium sodium niobate, KNN, a lead-free material, is a promising candidate for replacing PZT in applications such as sensors and actuators due to its environmental friendliness and high efficiency. However, producing pure KNN ceramic with a high density and a uniform fine-grained microstructure is challenging. This review discusses various methods used to produce KNN ceramics, including solid-state synthesis, centering, and special centering techniques. Solid-state synthesis produces KNN powders with low densities and large grain sizes, while centering requires careful control over temperature and atmosphere to achieve optimal results. Pressure-assisted centering and spark-plasma centering have shown promise in achieving higher densities than traditional centering methods. This article was authored by Barbara Malik, Jewish Karoza, Jitka Hreskak, and others.