In-N-Out's Cheeseburger is a single beef patty with American cheese, lettuce, tomato, onion, and their signature spread on a freshly toasted bun. The simplest burger on In-N-Out's famously short menu, it competes with Five Guys' Little Cheeseburger and Shake Shack's ShackBurger as a premium single-patty option that prioritizes fresh ingredients over gimmicks.