How can I reduce Cumulative Layout Shift (CLS) from ads?

We want you to be able to achieve the best possible scores for Google’s Core Web Vitals AND earn top dollar from your ads, so we made it a priority to solve ad-related Cumulative Layout Shift (CLS). We have a solution for those who run our Raptive Ads plugin and those who don’t, and both are quick and easy to enable! 

For Raptive Ads plugin users:

First, make sure you're running the Raptive Ads plugin version 1.0.45 or higher.

Click on "Raptive Ads" in your WordPress dashboard sidebar to get to the Raptive Ads plugin settings page:


Then simply check the box next to Enable solution to reduce ad-related CLS on the plugin settings page, save your changes, clear your site’s cache, and you’re all set!


Your CLS score should improve immediately, though it may take a few days for this to be reflected in the various Core Web Vitals measurement tools.

This setting does two crucial things:

First, it moves our ad insertion from a third-party request to live directly on the page via the plugin. This allows us to reserve space for ads as the page is being rendered, reducing ad-related CLS issues.

Second, it will apply a styling update to your ad spaces, setting a minimum height, to reduce page shift when ads refresh and, potentially, a different ad size serves in the ad slot.

Note:  If you are currently using an optimization plugin, like WP Rocket, be sure to exclude our ad scripts from being optimized; as that could have an impact on your ad performance and prevent your CLS option from working correctly.

We recommend adding the following list of exclusions in the WP Rocket File Optimization settings to prevent your ad scripts from being optimized:




Head over to WP Rocket > File Optimization > JavaScript Files to add these exclusions in the following settings, if you have them enabled:

Be sure to save your changes and clear your site cache after making these updates.

Note: If you're using a different site optimization plugin, other than WP Rocket, check out our guide here for a list of plugins and detailed instructions on how to add the exclusions.

For non-plugin users:

If you don’t run your ads through the Raptive Ads plugin, we have a similar, effective CLS solution for you!

Head to the Ad Preferences page in your Raptive dashboard, look for the User Experience section, and turn on the toggle next to “Reduce CLS from ads”. Make sure to save your changes:


This setting does two things. First, it reserves space for ads when the initial ads library loads. Second, it applies a minimum height to your ad spaces, to avoid potential page shift when an ad serves. These two optimizations greatly reduce ad-related CLS issues.

Note: If you’ve enabled the CLS setting within the Raptive Ads plugin, this Ad Preferences CLS setting will not have an effect on your site.

How much will this solution improve my CLS score?

With our CLS solutions, your ads should have a minimal or no impact on your CLS score. If you’ve additionally optimized your site to solve any non-ad CLS issues, you should have no problem achieving a CLS score in the “good” range!


Occasionally, ads that are larger than standard sizes may serve and cause some shift. In these cases, we think the increased revenue from these infrequent, larger ads is worth the trade-off. If you request it, we can turn off these ads from serving on your site. But the goal is to get into the “Good” range, not to achieve a perfect zero score — once you’re under 0.1, Google has said that there’s no bonus for further score improvements.

Will these CLS solutions affect my RPM?

We’ve performed extensive testing to ensure that your RPM and take-home revenue will not be negatively impacted by our CLS solutions!

Will my sticky video player cause CLS?

Your sticky video player is already optimized for CLS to minimize any shifting, so it won't have any impact on your CLS scores.

How can I check my CLS score?

Before testing, you’ll need to clear your site’s cache and give your site some time to allow the cache to rebuild. This step is crucial as your scores can be volatile until this process is done. We recommend waiting at least a day or two before testing for the best results.

The most immediate way to see the change in your Core Web Vitals is through Cloudflare. If you’re a Cloudflare user, you can enable their Browser Insights and see your Core Web Vitals performance in real time!

Google Search Console is another great resource, as it will give you a general idea of how pages are performing for CLS across your site. Search Console shows daily Core Web Vitals metrics as recently as two days in the past, so after enabling our CLS solution in the plugin, check back in a few days to start seeing the improvement to your CLS scores in Search Console.

You can also head to PageSpeed Insights to test individual pages and get specific details on what is affecting your Core Web Vitals scores. Your field data (which reflects your readers’ actual experience) should improve slowly, day by day, as it shows your average score over the past 28 days.

I’m still noticing some ad-related CLS issues affecting my score.

If you still see CLS issues that you believe are related to your ads, feel free to reach out to us! Every site’s ad layout is different so your specific ad setup may benefit from some customizations that our team is happy to help with. 

What else can I do to improve my CLS score?

After enabling our solution for ad-related CLS, you should see a marked improvement in your CLS score. But you may have other elements on your site other than ads that are causing CLS issues.

Check out our four-step playbook for how to diagnose and improve Core Web Vitals on your site, to identify and fix any additional CLS offenders.

As you test different pages on your site and work to improve CLS, focus first on mobile experience and scores. Google emphasizes mobile, so prioritize your optimizations for mobile and then desktop.

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