The current research focuses on the synthesis and characterization of sodium potassium niobate (KNN), a lead-free piezoelectric compound. The objective is to replace lead-based compounds like PZT using KNN-LST, which is sodium potassium niobate piezoceramic powder doped with lithium, antimony, and tantalum. To this end, solid-state method was employed to sinter the samples at 1110 °C with varying percentages of NiO sinter aid (0%, 0.75%, 1.5%, and 2.25%). X-ray diffraction analysis confirmed the formation of pure KNN-LST perovskite phase at 1110 °C with a composition containing 1.5% NiO. Scanning electron microscope images also demonstrated that cubic particles inherent in KNN were observed in samples with no NiO addition as well as those containing 0.75% and 1.5% NiO; however, these particles were transformed into cylindrical grains when incorporating 2.25% NiO. With an increase in the sintering percentage from zero NiO content to higher amounts, sample density also increases from approximately 85% up to its peak at around 94%, followed by a slight decrease by about 91%. Similarly, the dielectric coefficient increased from approximately850 without any contribution from NiO sinter addition up to1500 upon addition of 1.5%NiO sinter but then, it decreased again by approximately 1200 followed by addition of 2.25% NiO sinter. Conversely, dielectric loss initially reduced from roughly 0.14% during no NiO sinter addition by merely 0.04% during 1.