Mario Kart 8 Deluxe supports up to 12 racers in a single online race.
This limit applies to the standard online racing format, where players compete over a course from the Mario Kart 8 Deluxe track list. The game supports online matchmaking through Nintendo Switch Online and can also place players from different regions into the same race.
The number 12 is sometimes confused with local multiplayer limits. A single Nintendo Switch console supports fewer simultaneous local racers, depending on the mode and setup, while online races can reach the full twelve-player field. Wireless local play between multiple consoles has its own limits as well.
Mario Kart 8 Deluxe launched for Nintendo Switch in April 2017. It is an enhanced version of Mario Kart 8, adding all previously released downloadable content, new characters, revised Battle Mode arenas, and features such as Smart Steering and double-item boxes.