OpenSea charges a fee of 2.5% for sellers on each successful sale, as well as a 2.5% fee for buyers on each purchase. In addition, there may be additional fees associated with using specific payment methods, such as gas fees for transactions on the Ethereum network.

There are also additional fees for certain premium features on the platform, such as a 3% fee for using the "Instant Sale" feature, which allows sellers to sell their items at a fixed price without going through the auction process.

Overall, OpenSea's fee structure is fairly competitive compared to other digital marketplaces, although the fees can add up quickly for high-value transactions. However, the platform provides a range of tools and features to help buyers and sellers manage their transactions, including automated bidding and notification systems, as well as detailed analytics and reporting on sales activity. It is important for users to carefully review and understand the fee structure before buying or selling on OpenSea to avoid any unexpected costs or fees.