The responsibility for shipping costs in returns and exchanges varies depending on the platform policy and the specific reasons. If the return or exchange is due to product quality issues or seller errors (such as sending the wrong item), the shipping costs are usually borne by the seller. If it is due to the buyer's reasons (such as wrong size, dislike, etc.), the shipping costs are usually borne by the buyer. Some platforms may offer shipping insurance, which buyers can choose to purchase at the time of purchase to reduce the shipping costs associated with returns and exchanges.