Mobile display size

320x480Mobile Interstitial

Also called Full-screen portrait, Mobile portrait interstitial.

Width
Height
Aspect ratio
Area

Actual size

Rendered at true pixel dimensions. On a narrow screen it scales down to fit.

320 × 480

Where it runs

Full-screen between content views — typically a page transition or an app level break.

Why it is used

The full-screen portrait mobile unit. Commands high CPMs because it takes the entire viewport, and consequently records very high viewability and strong measured attention.

What to watch for

The most intrusive standard format, and the one most exposed to policy risk. Interstitials that block content or appear on entry are penalised by Google's page experience signals, and mis-timed placements produce accidental clicks at scale. Frequency capping is not optional on this unit.

File weight for standard display is commonly specified at around 150 KB initial load, but publisher specs vary and the figure that governs is always the one written into the insertion order. Check it before trafficking rather than after a creative is rejected.

Related sizes

Dimensions follow IAB Tech Lab display guidelines. Placement and performance guidance is practitioner knowledge, last verified July 2026.