Disney Parks are designed to handle massive crowds. The Magic Kingdom can allegedly hold more than 100,000 guests, but through phased closures Disney limits park attendance to levels more conducive to guest safety and enjoyment.
How to Beat the Crowds
Likelihood of Park Closure
Since as of 2020 a theme park reservation is required to enter each guest's first park of the day, we expect park closures to be rare in the future.
All four Disney World theme parks have reached some level of closure in the past. As the most visited theme park in the world, Magic Kingdom is the park most likely to experience capacity-based closures during busy times of year. Due to its size, EPCOT is the least likely to close, and has not done so in recent memory. Hollywood Studios and Animal Kingdom rarely close, but their smaller capacities still make them more likely to close than EPCOT.
Closures may still happen at Disney's water parks, Blizzard Beach and Typhoon Lagoon, which do not require reservations. Still, water park capacity closures have been rare in recent years, happening more at Blizzard Beach than at Typhoon Lagoon, and generally being limited to July and near Easter.
Parking
Typically parking lots close for capacity-related reasons before the theme parks do, even if the park itself is not at a phased closure yet. When this happens, Disney may divert cars to an alternate parking lot and provide bus transportation to the park whose lot is closed. For example, sometimes the Hollywood Studios lot fills and guests are diverted to the gigantic EPCOT parking lot. When this happens, follow posted signs and instructions carefully.