Apple's iPhone 6 is the best-selling iPhone model of all time. These iPhone models have broken sales records since their introduction in 2014, giving Apple's competitors another reason to work harder for smartphone supremacy. Although the Cupertino, CA-based company tends not to break down iPhone sales figures by particular models, it's estimated that roughly 222.4 million units of iPhone 6 models have been sold.

Released in 2013, the iPhone 5 accounted for 143.4 million unit sales, and the iPhone 5S recorded 163.7 million unit sales. These were Apple's top sellers until the 2014 release of the faster iPhone 6 and the larger Phone 6+.

By mid-2019, iPhone sales had dropped off considerably from the peak achieved with the iPhone 6 and 6+, and the industry was hotly anticipating a new crop of smartphones with 5G capabilities in 2020, which promised groundbreaking features. There was even some anticipation that the iPhone 12 with 5G would surpass the iPhone 6's sales record.