You can let Google automatically optimize the size of your Adsense ad units on mobile. There’s no need to create new ad units or change your Adsense ad code. Your existing ad units will change their size based on the context and orientation of the user’s device, and may show larger ads, full-width ads, etc. As a result, more ads will be eligible to fill your ad units, potentially leading to an increase in revenue.

Google automatically optimize Ads Limitations
This optimization setting only works on mobile-optimized sites. In addition, Google is unable to optimize the following types of ad unit:

  • Iframed ad units (this includes ad units served through ad servers such as Google Ad Manager)
  • Ad units within a parent container that has restricted dimensions (e.g., a fixed height, overflow: hidden, etc.).

Preview automatically optimized ads on your site
You can preview the behavior of this optimization setting on your site before you turn it on.

On a mobile device

  • Visit your site, and add #google_responsive_slot_preview to the end of your page’s URL.
  • Refresh the page.
  • Toggle the orientation between landscape and portrait to see different ad sizes.

On desktop using the Google Chrome browser


Subscribe to GetAdsense Newsletter

Discover Google AdSense top secrets to making more money using AdSense ads on your sites. We deliver all the essential soultion direct to your email inbox. Subscribe to GetAdsense today.


  • Open your site in a new tab, and add #google_responsive_slot_preview to the end of your page’s URL.
  • Toggle “Device mode” on. See Simulate Mobile Devices with Device Mode for instructions on how to do this.
  • Select a mobile device from the drop-down list (e.g., Pixel 2 or iPhone 6/7/8).
  • Refresh the page.
  • Toggle the orientation between landscape and portrait to see different ad sizes.

Note: These steps will be similar on other browsers. See your browser’s documentation for more information.

Turn on the ad sizes optimization setting

  • Sign in to your AdSense account.
  • Click Optimization.
  • On the “Opportunities” page, in the “Optimization settings” section, click the Down arrow next to “Ad sizes”.
  • Select an option:
    • Optimize 100% of mobile page views (recommended)
      Google will automatically optimize all of your Text & display page views to have the best ad unit sizes
    • Optimize 50% of mobile page views
      Optimize 50% of your text & display page views so that you can compare the impact. Click View report to see the comparison on your Reports page.
    • Don’t optimize.

Google won’t optimize your text & display page views.

Did you find this helpful and informative?