The main differences between the iPhone 13 and iPhone 13 Pro Max go down to the new 120Hz adaptive refresh ProMotion display and improved cameras. However, you can also find other differences like battery performance, colors, and price.
iPhone 13 comes in 6.1 inches, resolution of 2532 x 1170/460, and maxes out at 512GB storage. In comparison, the iPhone 13 Pro Max has a 6.7 inches screen with a resolution of 2778 x 1284/458 and goes to a one terabyte variant for storage-savvy users.