How to get Google to optimize your ad sizes automatically

DoubleClick For Publishers / Google Ad Manager Ad Optimization
Last updated: June 14, 2022 | by Kean Graham
How to get Google to optimize your ad sizes automatically

This post was most recently updated on June 14th, 2022

Remember when you wished AdSense had the same feature as Ad Exchange, called “Flexible Sizes”? With the recent product release, Google can now optimize your mobile ad sizes automatically so more ads will be eligible to serve on your ad units and increase earnings.

The difference is – in Ad Exchange, you can only allow smaller sizes for as long as it fits the original container. While in AdSense, Google can allow smaller or bigger ads and even full-width ads.

Here are some of the limitations

  • It only works on mobile-optimized sites.
  • It won’t work on iframe ads – including those served via an ad server, like Google Ad Manager
  • It won’t work on ad units within a parent container with restricted dimensions. For example, overflow: hidden, fixed height.
  • It only works on subsequent page views and not the first user page view. Google will leverage the first-page view to get the optimization settings.

How to turn on ad sizes optimization

Step 1: Access your AdSense account

Step 2: Click Optimization, then the gear icon

automatic experiments off

Step 3: Choose “Optimize 100% of mobile page views”

ad sizes

Step 4: The settings will automatically be saved

How to preview automatically optimized ads

If using mobile:

Step 1: Open your site on a browser

Step 2: Add #google_responsive_slot_preview to the end of the URL

Step 3: Refresh the webpage

Step 4: Position your phone to switch between portrait and landscape orientation to see the ad sizes

If using desktop:

Step 1: Open your site on a browser

Step 2: Add #google_responsive_slot_preview to the end of the URL

Step 3: Right-click > Inspect to open Dev Tools

Step 4: Turn on Device Mode

turn on device mode

Step 5: Refresh the page

Step 6: Select mobile device you’d like to test from the dropdown

select a device

Step 7: Click to rotate between portrait and landscape orientation and see the different ad sizes

landscape rotate

You can also see the steps mentioned above implemented in our video below:


Although this is an awesome product update from Google, it, unfortunately, does not cover all ads. You still need to implement various ad optimization techniques, run header bidding and more to maximize your ad revenue. Not sure how to get started? Let MonetizeMore’s team of ad ops experts help! Sign up today.

"NET RPM increased 61.3% compared to our yearly average before working with MonetizeMore, and NET Revenues increased 54.8%. There is no doubt that turning over the day-to-day management of our ad inventory to MonetizeMore's team of experts has been the right move for our business."


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