Desktop 4K screen size & viewport

The Desktop 4K renders web pages at a CSS viewport of 3840 × 2160 in portrait (2160 × 3840 in landscape).

What these numbers mean

3840 × 2160 is the CSS viewport size — the coordinate space your layout, media queries and vw/vh units work in. It is not the hardware pixel count: the Desktop 4K packs more physical pixels behind each CSS pixel (its device pixel ratio), which is why images meant for it should be exported at 2× or 3×.

For a desktop / laptop this size, a layout should already be at its multi-column / tablet breakpoint.

Targeting it in CSS

/* Styles for viewports up to the Desktop 4K */
@media (max-width: 3840px) {
  .container { padding-inline: 16px; }
}

/* Exactly the Desktop 4K in portrait */
@media (width: 3840px) and (height: 2160px) { /* … */ }

Common things that break at 3840px wide

• Fixed-width elements wider than 3808px (content minus typical padding) cause horizontal scroll.
• Tap targets under 44×44 CSS px are hard to hit.
• Sticky headers taller than ~15% of 2160px eat too much of the screen.
• Text set below 16px triggers zoom-on-focus in form fields on iOS.

Other Desktop & laptop sizes