Preheat the oven to 350 degrees F (175 degrees C).

Slice off crusts from stale bread slices. Brush bread on both sides with melted butter. Cut bread slices into small cubes. Sprinkle with garlic salt. Arrange cubes on an ungreased cookie sheet.

Bake in the preheated oven until browned, about 15 minutes. Let cool completely, then store in a covered container or plastic bag.