you can specify one or more sizes as the size set for an ad slot. When using the responsive ad functionality, you can also choose an alternate size set based on the size of the browser.
For example, you can specify that if the browser is larger than 1024×768, then ads sized either 970×90 or 728×90 should serve, whereas for smaller browsers only 468×60 ads should serve. You may want to specify different size setups for desktop, tablet, and mobile devices.
Mappings are ordered automatically so that the best-sized creative is used. You can specify a default ad unit size to serve an ad that will fit any browser size if none of the other sizes matches those of the visitor’s browser.
Responsive ad tagging functions for GPT will work in both asynchronous and synchronous modes.
The Viewport represents the minimum browser’s size that the mapped Request Size is going to be applied to. Only a single Viewport size can be set for each line.
Supported size formats are:
Width x Height:1024x768
The Request Size represents the Ad request sizes that are going to be applied to the associated Viewport. The Request Size can contain multiple sizes including Fluid.
Below is an example of Size-mapped ad :
If you are interested in testing out this format, please contact your account manager and they will be happy to create the right tag for your needs !!