Mobile display size
320x50 — Mobile Leaderboard
Also called Mobile banner, Smartphone banner.
- Width
- 320px
- Height
- 50px
- Aspect ratio
- 32:5
- Area
- 16,000px²
Actual size
Rendered at true pixel dimensions. On a narrow screen it scales down to fit.
Where it runs
Anchored to the top or bottom of a mobile viewport, or inline between content blocks.
Why it is used
The standard mobile banner and the highest-volume mobile display size. Its shallow height makes it unobtrusive, which is why it is the usual choice for a sticky anchor unit that stays visible throughout a session.
What to watch for
Fifty pixels of height is very little room for a message, and sticky anchor placements sit close to interface controls — which is the classic source of accidental clicks. An unusually high CTR on this unit is more often a sign of misclicks than of good creative.
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.