Ad Slots

An Ad Slot in Bidkernel maps to a physical space on your webpage where an ad will render.

Defining Ad Slots Link to section

You define slots within an Environment. For each slot, you must provide:

• Slot Path / ID: The unique identifier for the slot (e.g., div-gpt-ad-top-leaderboard).
• Default Sizes: The baseline accepted creative dimensions for this slot, used when no specific Viewport matches or is configured (e.g., [[728, 90], [970, 250]]).
• Viewport Overrides: Responsive size mappings based on defined Viewports. This allows you to serve different ad sizes depending on the user's screen size.

Viewability and Lazy Loading Link to section

Bidkernel's SDK has built-in smart rendering aimed at maximizing your viewability scores and minimizing wasted bid requests.

The 50% + 1s Threshold Link to section

Bidkernel implements the standard IAB (Interactive Advertising Bureau) viewability threshold Source: MRC Viewability Guidelines View Citation → by default. Ads are considered "viewable" (and consequently are fully rendered and tracked) when 50% of the ad's pixels are in the viewport for at least 1 continuous second.

Auto-Refresh Link to section

When configuring a slot, you can define custom refresh rates. The Bidkernel SDK manages the timers automatically, pausing the refresh countdown if the user switches browser tabs or scrolls the ad out of view.