Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for during a first time period, identifying first digital components for presentation when an electronic document is presented at the client device; generating, using priority indicators assigned to each first digital component, a digital component priority queue that specifies an order of presentation of the first digital components; transmitting, to the client device, the electronic document, the first digital components, and the digital component priority queue; during a second time period that occurs after the first time period, identifying a second digital component for presentation when the electronic document is presented at the client device; and updating the digital component priority queue at the client device, including causing the second digital component to be inserted into the digital component priority queue based on a priority indicator assigned to the second digital component.