What is the difference between potassium gluconate and potassium citrate?

Both potassium supp: Citrate acts as a buffer/alkali in conditions with high acid (acidemia). Gluconate has a glucose content in it. They both act as potassium supplement and selected on the basis of clinical situation.

Not much, but: Potassium citrate helps prevent kidney stone disease due to its citrate content that gets excreted in the urine. Otherwise, both are potassium salts to supply potassium to people who have low potassium blood levels. Taking potassium regularly without a doctor's advice is risky, even if it is over the counter.