Nintendo began prototyping Mario Kart World in 2017.
The earliest prototypes were made for the original Nintendo Switch, shortly before Mario Kart 8 Deluxe was released. The team was already considering how to move the series beyond its established racing formula, rather than simply adding another set of conventional courses.
By the end of 2017, Nintendo Entertainment Planning & Development had officially begun development. The concept gradually expanded toward an open world with connected roads, off-roading, boat racing, rail grinding, and free exploration.
The project’s 2017 starting point is different from its hardware transition date. Development moved to Nintendo Switch 2 in 2020 after the original system struggled with the demands of an open-world racing game containing 24 drivers.