What is the 300×1050 IAB Portrait?
The 300 x 1050 Portrait is an IAB “Rising Star” ad unit. It is essentially a massive vertical canvas that appears in the sidebar of websites, offering three times the vertical space of a standard Half Page (300×600) ad.
Because of its sheer size, it is highly prized for brand awareness campaigns. It allows advertisers to divide the creative into three distinct sections (like a filmstrip) or use one continuous, immersive graphic that stays on screen for a long time as the user scrolls.
Why Use the 300×1050 Size?
- Unmissable Visibility: It occupies a huge portion of the screen real estate without interrupting the content flow.
- Rich Media Potential: The extra height is perfect for interactive features, video embeds, or complex animations.
- Premium Inventory: This size typically commands higher CPMs due to its “Rising Star” status.
Technical Specifications
- Dimensions: 300 pixels wide by 1050 pixels tall.
- File Weight: 250KB (Max).
- File Formats: JPG, PNG, GIF, HTML5.
Best Practices for Design
Utilize the vertical space by telling a story from top to bottom. Place your logo at the very top (so it’s seen first) and your call-to-action (CTA) at the bottom or floating in the middle to catch the user’s eye as they scroll down the page.