HBO Max previously offered a limited selection of 4K titles through its ad-free plan ($16/month), but new Max subscribers now need the Ultimate plan to get 4K support ($20/month). If you signed up for HBO Max's ad-free plan before May 23, you will still get 4K streaming for at least six months before needing to upgrade. Though 4K support is now more expensive, Warner Bros. Discovery has expanded Max's library of 4K content as part of the rebranding. At launch, Max has more than 1,000 movies and TV episodes in 4K, which is almost eight times the amount of 4K content that was on HBO Max. Many 4K titles also support HDR (high dynamic range) using the HDR10 and Dolby Vision formats. Some notable titles in 4K on Max include "The Last of Us," "Game of Thrones," the "Harry Potter" films, and classics like "The Wizard of Oz" and "Goodfellas." You can find a full list of 4K titles and supported 4K streaming devices on Max's website.