Nintendo announced a mobile Mario Kart title in January 2018. A closed Android beta ran from late May to early June 2019 before the worldwide release in September of that year. The game reached 90.1 million downloads in its first week — the highest first-week figure for any Nintendo mobile title — and surpassed 10 million downloads within a single day of launch. Revenue in the first week reached $12.7 million, the third-highest opening for a Nintendo mobile game behind Fire Emblem Heroes and Super Mario Run. Downloads exceeded 200 million by April 2021, with total revenue surpassing $200 million, making it the second-highest-grossing Nintendo mobile game behind Fire Emblem Heroes.
Mario Kart Tour operates on a tour system in which new themed tours, each named after a real-world city, a Mario series character, a Nintendo game, or another theme, rotate on a two-week cycle beginning each Wednesday. Each tour contains twelve to eighteen cups. A cup consists of three courses and a bonus challenge. Courses are primarily remixed or adapted from previous Mario Kart entries; courses reworked from Super Mario Kart circuits are labeled RMX courses and feature altered layouts and new mechanics.
The game deviates from series conventions in several ways. Acceleration and some jump boosts are handled automatically. A point-based scoring system replaces the traditional win/loss outcome, rewarding players for tricks, item use, and race placement simultaneously. Speed classes available are 50cc, 100cc, 150cc, and 200cc, though the latter two tiers are restricted to subscribers of the paid Gold Pass.
A Frenzy mode activates when a driver collects three identical items from a single item box, allowing repeated use of that item for a short window. Each character carries a designated Special Skill item that they are more likely to receive from item boxes. The game launched in portrait mode only; landscape support was added in a July 2020 update. Mii racers became playable in March 2022.
The game initially used bots with real player usernames rather than live multiplayer. A multiplayer beta ran for Gold Pass subscribers in December 2019. Full multiplayer, supporting races against up to seven other players, launched on March 8, 2020. Standard Races open to all players are limited to 100cc; Gold Pass subscribers access 150cc and 200cc Gold Races. A multiplayer ranking system ranges from F through A and continues to S through S+9 for Gold Pass subscribers.
Mario Kart Tour launched with a gacha mechanic called the Spotlight Pipe, in which players spent the in-game currency Rubies on randomized pulls to obtain drivers, karts, and gliders. Critics widely condemned the system, comparing the cost of the Gold Pass subscription unfavorably to competing services. The game was also criticized for making progression artificially difficult without spending.
On September 2, 2022, Nintendo announced the removal of the Spotlight Pipe gacha system, replacing it with a standard shop carrying both current and returning items. Battle mode returned in the same October 2022 update.
A lawsuit filed in May 2023 on behalf of a minor alleged that the Spotlight Pipe system encouraged gambling-like behavior among children and called for refunds for all US minors who purchased Rubies. The suit cited violations of California business law and Washington State's Consumer Protection Act.
Nintendo ceased releasing new content on October 4, 2023, shifting the game into a rerun cycle of previous tours. Much of the game's content, including original Tour tracks, was ported as downloadable content to Mario Kart 8 Deluxe through the Booster Course Pass. Several Tour-originated courses were also included in Mario Kart World, the next mainline entry. A 2025 rerun of the Sunshine Tour included minor new content timed to the launch of Mario Kart World, marking the last new material added to the game.
Mario Kart Tour won the Racing Game of the Year award at the 23rd Annual D.I.C.E. Awards and was nominated for Favorite Video Game at the 2020 Kids' Choice Awards.