PageSpeed Insights and Raptive Ads

If you use Google PageSpeed Insights (PSI), understanding the distinction between Field Data and Lab Data is essential. While Lab Data provides simulated performance metrics in a controlled environment, Field Data offers insights based on real user experiences. 

When you generate a PageSpeed Insights test, you will receive two sets of results, which is the Field Data and Lab Data. More details to come for you to understand both data types.

Field data

The top part of the page shows the Core Web Vitals Assessment, which is known as the "field data" in the PSI report. Here’s an example:


These are the primary metrics (Largest Contentful Paint (LCP), First Input Delay (FID), Cumulative Layout Shift (CLS)) that are of the most importance, as they come from real-world user data and are the only metrics that Google uses for SEO and rankings.

Field data also takes things like asynchronous load, ad code, and user experience into account, so it is data based on what an actual user sees.

It’s highly recommended to focus on optimizing your site for these metrics, so that it passes all Core Web Vital metrics. 

Note that Raptive ads/scripts are optimized for Core Web Vitals to minimize any impact on the results that appear in the field data. 

Lab data

The bottom part of the PSI test, Diagnosis performance issues, is the "lab data" result. So the cumulative performance number (1-100), which lists data for the Total Blocking Time (TBT), Speed Index and etc. Here’s an example of the lab data report section:

These are lab metrics and are of a lesser concern, as they have no direct impact on how real users experience your site or on Google rankings.

It’s also important to note that the lab data is a computer-generated test that can't differentiate between your content or ads, so everything is looped together and it thinks your ads need to be optimized. Raptive ad scripts are often picked up in the lab data test results in a very inaccurate and misleading way.  

Regarding the various metrics in this section of the PSI test, it’s recommend that you focus on the Core Web Vitals field data and not on the lab metrics data (speed index, TBT, etc.).

Raptive Ad Scripts Impact on Site Speed

When it comes to your site speed, Raptive ads are designed to load asynchronously (after your site content loads) so that they never interfere with site performance and how quickly readers can view your content. 

If you use site speed analysis tools like PSI, you may notice ad-related scripts showing in the speed test results. For example, in PSI, under the Opportunities > Reduce unused JavaScript section, you may see ad-related scripts as follows:

And other ad-related scripts may also appear under the Diagnostics > Reduce the impact of third-party code sections as follows:

These ad-related scripts seen in the above sections of the PSI results page are very common and are needed for the ad bidding process to work properly. We load these scripts in a way that prioritizes your site content to load first so they won't impact load speed.

However, If you’re wanting to improve the lab data scores, we do have a deferred ad loading option that could be enabled. This will help keep most ad-related scripts from impacting your lab result scores.  But we don’t recommend enabling that option, since it could have an impact your RPM by about 1% - 5%. 

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