iPhone 17 Pro Max: Screen Size & CSS Viewport

At 440×956 CSS pixels the iPhone 17 Pro Max is the widest iPhone viewport currently available, and its user base skews toward premium consumers who engage deeply with web content. ProMotion up to 120 Hz makes scroll animations, transitions, and parallax effects appear dramatically smoother on this device — and makes any janky or stuttering animation equally more noticeable.

The 440px viewport width matters because it is the widest single-column mobile layout most users will encounter. If your mobile design applies max-width to text content at 320px or 375px and then lets it expand freely to 440px, the resulting line length at 440px may be too long for comfortable reading. Explicitly test your body text at 440px and consider whether a max-width or comfortable reading width constraint is warranted.

Ceramic Shield 2 on both front and back means these phones are used in rougher conditions and take more wear. They appear more in outdoor, commute, and on-the-go contexts — locations where users are more likely to experience variable lighting, mobile data, and one-handed interaction. Your mobile layout should be tested under these conditions, not just at a desk.