To request an ad with multiple sizes, pass a string of comma-separated sizes to
the data-multi-size attribute. Each size in the list must be a width followed
by a lowercase 'x' followed by a height. Secondary sizes must not be larger than
their corresponding dimensions specified by the width and height attributes,
or the data-override-width and data-override-height attributes, if they are
set. Further, the secondary sizes must not be smaller than 2/3rds, in any of the
two dimensions, of their primary size counterpart, unless
data-multi-size-validation is explicitly set to false. See below for some valid and invalid examples.
Note that multi-size slots may have unexpected interactions with
layout="responsive". For this reason it is strongly encouraged that multi-size
slots use layout="fixed".
Below the term primary size refers to the width and height pair specified by the width and height attributes of the tag.
data-multi-sizeA string of comma separated sizes, which if present, forces the tag to request an ad with all of the given sizes, including the primary size. Each individual size must be a number (the width) followed by a lowercase 'x' followed by a number (the height). Each dimension specified this way must not be larger than its counterpart in the primary size. Further, each dimension must be no less than 2/3rds of the corresponding primary dimension, unlessdata-multi-size-validationis set to false.data-multi-size-validationIf set to false, this will allow secondary sizes (those specified in thedata-multi-sizeattribute) to be less than 2/3rds of the corresponding primary size. By default this is assumed to be true.
Example - Valid multi-size request
<amp-ad
width="728"
height="90"
type="doubleclick"
layout="fixed"
data-slot="/6355419/Travel"
data-multi-size="700x90,700x60,500x60"
>
</amp-ad>Example - Invalid multi-size request (multi-size size is too small relative to overrides)
<amp-ad
width="320"
height="50"
type="doubleclick"
layout="fixed"
data-slot="/6355419/Travel"
data-override-width="728"
data-override-height="90"
data-multi-size="300x25"
>
</amp-ad>Example - Invalid multi-size request (last multi-size size is too small)
<amp-ad
width="728"
height="90"
type="doubleclick"
layout="fixed"
data-slot="/6355419/Travel"
data-multi-size="700x90,700x60,300x25"
>
</amp-ad>Example - Valid multi-size request (ignores minimum size constraint)
<amp-ad
width="728"
height="90"
type="doubleclick"
layout="fixed"
data-slot="/6355419/Travel"
data-multi-size="700x90,700x60,300x25"
data-multi-size-validation="false"
>
</amp-ad>