Universal display size
250x250 — Square
Also called Square pop-up.
- Width
- 250px
- Height
- 250px
- Aspect ratio
- 1:1
- Area
- 62,500px²
Actual size
Rendered at true pixel dimensions. On a narrow screen it scales down to fit.
Where it runs
Sidebar or in-content where a compact unit is needed.
Why it is used
A compact square for positions too narrow to take a 300x250. It fits comfortably inside a mobile viewport, which makes it one of the few square units that works on both desktop and phone without a separate creative, and it appears in older universal ad packages that some publishers still traffic against.
What to watch for
Meaningfully less demand than 300x250 for very little saved space. Usually only worth supporting when the layout genuinely cannot accommodate 300 pixels of width.
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.