Smart Banners are new ad units (as of v6.0.0) that will render screen-wide banner ads on any screen size across different devices in either orientation. Smart Banners help deal with increasing screen fragmentation across different devices by "smartly" detecting the width of the phone in its current orientation, and making the ad view that size.
To use Smart Banners, you will need to use one of the following ad size constants:
SmartBanner(Windows Phone 8)
In portrait mode on phones, this will make the ad view either 320x50 or 360x50 in size, depending on whether the device is widescreen. In landscape mode on phones, this will make the ad view anywhere from 480x32 to 682x32 depending on the height of the device.
When an image ad won't take up the entire allotted space for the banner, we'll center the image and use a hexagonal textile filler (see image) to fill up the remaining space. Note that AdSense backfill ads will be centered and have "transparent" filler.
For a full set of supported sizes and what kind of ads will appear, see the table below.
|Size||Where it'll appear||Text ads?||Image ads?|
|320x50||iPhone, Windows Phone 8, and most Android phones in Portrait||Yes||Yes|
|360x50||Android widescreen devices in Portrait||Yes||Yes, with 20px fill on each side|
|480x32||iPhones in Landscape||Yes||No|
|533x32, range of sizes from 480x32 to 682x32||Android and Windows Phone 8 devices in Landscape||Yes||No|
|768x90||iPads in Portrait||Yes||Yes|
|1024x90||iPads in Landscape||Yes||Yes, centered with 150px fill on each side|
|800x90||Android tablets in Portrait||Yes||Yes, centered with 36px fill on each side|
|1280x90||Android tablets in Landscape||Yes||Yes, centered with 276px fill on each side|
|600x90||Kindle Fire in Portrait||Yes||No|
|1024x50||Kindle Fire in Landscape||Yes||No|
Note: Most mediation ad networks do not yet support Smart Banners—check with the particular network you plan to use.