Overall iPhone revenue grew 6%, in the first sign of how the iPhone 16 is faring in the market. Apple's newest devices came out Sept. 20, giving Apple about a week of new product sales in the quarter. It's still Apple's most important product, accounting for nearly 49% of the company's overall sales.

Sales of the iPhone 15 were "stronger than 14 in the year-ago quarter, and 16 was stronger than 15," Apple CEO Tim Cook told CNBC's Steve Kovach.