Apple · iOS 15.0
@media (min-width: 390px) and (max-width: 390px)What Is PPI and Why Does It Matter for Screens?
PPI is the single number that determines whether a screen looks razor-sharp or grainy. Learn how it is calculated and what it means for this device.
Read articleCSS Pixels vs Physical Pixels: The Complete Developer Guide
Your screen has millions of hardware dots. Your CSS has none of them. Learn how Device Pixel Ratio bridges the gap.
Read article