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Audit Google Ad Performance With Lighthouse

Audit Google Ad Performance With Lighthouse

Implementing Google Ads can be complicated. If done incorrectly, it negatively impacts your website’s performance. Fortunately, there is a new Google Lighthouse plugin tailored specifically to find problems with your Google ad implementation.

Google Publisher Ads Plugin

Publisher Ads Audits for Lighthouse is a plugin created to help surface issues with your Google ads setup. It’s open source and hosted on Github. It’s currently developed specifically for users of Google Ad Manager and uses a series of automated audits to spot problems.

Running the Plugin From Chrome

To get started simply open the Chrome Developer tools and navigate to the Lighthouse tab. You’ll find a (beta) Community Plugin called Publisher Ads.

The Publisher Ads Audit.
The Publisher Ads Audit.

It can be run like any other Lighthouse audit - either on its own or in combination with the other audits available.

Running the Plugin on the Web

If you don’t use Chrome, Google helpfully hosts a web page that can run the Publisher Ads audits as well. This is useful to get a second datapoint other than your own browser. You can find it here: https://developers.google.com/publisher-ads-audits/

Publisher Ads In Action

When we previously discussed Google ad performance impact, we looked at a few sites which saw a large slowdown when ads were enabled. One of those was CNN.com. We decided to see what the plugin could tell us about the ad setup on their site.

CNN.com Audit Results

Like most of the Lighthouse audits, the site is given an overall score, and then individual audit problems are surfaced below.

The Publisher Ads Audit Results.
The Publisher Ads Audit Results.

Duplicate Tag Loads

CNN is loading the exact same Google Publisher tag twice. This is needlessly wasteful of bandwidth and impacting load time.

Duplicate loads affecting performance.
Duplicate loads affecting performance.

Parallel Bid Requests

We also see that CNN is gathering bid requests in serial, and could potentially make both of those bid requests at the same time to speed things up. Tools like Request Metrics could show problems like this.

Synchronous requests slowing down load times.
Synchronous requests slowing down load times.

Slow Requests Blocking Your Ads

Ads aren’t always slow because of ad providers alone. Oftentimes other resources on your site will block the ad requests from doing their work. The Publisher Ads plugin will also show you which resources are blocking your ads from completing.

Bottleneck requests slowing down your website.
Bottleneck requests slowing down your website.

Many Helpful Suggestions

Publisher Ads contains over 20 audits in related to Google ads and common implementation mistakes. Not only will it show you which audits fail, but also which pass, and by how much.

Passing Google Ads audits.
Passing Google Ads audits.

Conclusion

The Publisher Ads Lighthouse audit is a great way to get started with optimizing your Google ads implementation. It suffers from the same issues all synthetic tests have, but it should certainly be a part of your ongoing Google ad performance monitoring.

Another part of your strategy should be monitoring your site’s performance with Request Metrics. We’ll tell you whether your changes are having a meaningful impact on your actual users, and not just in Google Lighthouse.

Eric Brandes
CTO Request Metrics