300x250

The 300x250 ad unit, commonly referred to as the medium rectangle, is a digital display advertising format measuring 300 by 250 pixels. It is one of the most widely used IAB standard ad sizes and is designed for both desktop and mobile environments.

Placement and formats: It is versatile and commonly placed within article content, sidebars, and app content. It supports static image creatives (JPG, PNG, GIF) as well as HTML5, rich media, or video, delivered via ad servers or programmatic platforms. It typically uses a clickTag for tracking clicks.

Delivery and compatibility: The size is defined by IAB to enable consistent cross-platform delivery. Ad networks, exchanges, and ad managers such as Google Ad Manager and AdSense support 300x250 tags, and the creative can be served through various formats and targeting options.

History and significance: Since the mid-2000s, the 300x250 size has been widely adopted as a flexible, page-friendly unit. It is often paired with other standard sizes, such as 336x280 or 728x90, to cover multiple placements. It remains a staple for display campaigns and is frequently requested by advertisers seeking a balance between visibility and page footprint.