Our experiments show that full-width In-article ads perform better on mobile devices in portrait mode. To help increase revenue, our In-article ad units automatically expand to use the full width of the user's screen when their device is orientated vertically.
However, if you don't want your In-article ad unit to automatically expand in this way, you may modify your ad code to disable this behavior. Keep in mind that by doing so you may decrease your potential earnings.
Disable full-width ads example
To disable full-width In-article ads, add the data-full-width-responsive parameter to your In-article ad code like this:
<script async src="https://pagead2.googlesyndication.com/pagead/js/adsbygoogle.js?client=ignored1234567890123456" crossorigin="anonymous"></script>
<ins class="adsbygoogle"
style="display:block; text-align:center;"
data-ad-layout="in-article"
data-ad-format="fluid"
data-ad-client="ignored1234567890123456"
data-ad-slot="5678"
data-full-width-responsive="false"></ins>
<script>
(adsbygoogle = window.adsbygoogle || []).push({});
</script>