Potassium citrate (KC) and potassium lactate (KL) are considered as salt replacers due to their saltiness, processing advantages, and health benefits. However, the obvious bitter taste associated with these compounds has limited their use in salt substitutes. Despite this challenge, little attention has been paid to improving their sensory properties. This study provided evidence that dietary polysaccharide carrageenan can effectively mask the bitterness of KC and KL by specifically binding K+ and forming double helix chains. A highly accurate prediction model was then established for the saltiness and bitterness of low-sodium salts using mixture design principles. Three low-sodium salt formulas containing different potassium salts (KC, KL, KCl), NaCl, and carrageenan were created based on the prediction model. These formulas exhibited favorable saltiness potencies (>0.85) without any noticeable odor, preserving the sensory characteristics of high-sodium food products like seasoning powder while significantly reducing their sodium content. This research provides a promising approach for the food industry to formulate alternative low-sodium products with substantially reduced sodium content, potentially contributing to decreased salt intake.