Proton pump inhibitors (PPIs) have several limitations to their efficacy including insufficient acid suppression, slow onset of action, and variable efficacy among patients due to CYP2C19 metabolism. Potassium-competitive acid blockers inhibit H+-K+-ATPase in a reversible and K+-competitive manner, are novel acid suppressive drugs with rapid onset of action, meal independence, and prolonged control of intragastric acidity compared to PPIs. Potassium-competitive acid blockers exhibited non-inferior therapeutic efficacies on reflux esophagitis, gastric ulcers, and Helicobacter pylori eradication. The review is focused on the unmet needs across the acid-related diseases and recent updates on clinical studies using vonoprazan and tegoprazan.