Core Web Vitals and Cookie Consent notice

20. July 2021


If a part of your traffic comes from European countries or California then your website possibly uses some implementation of Cookie Consent. Basically it is a banner that pops-up in the center of a viewable page or is anchored to the bottom or the top of the website. It informs your visitors how their private data is used and who has access to this data.

How can Cookie Consent affect core-web-vitals?

The Cookie Consent is primarily designed for visitors to get some advanced possibilities on how to protect their privacy. However, with advantages come disadvantages. In this case - mainly for publishers.

The Cookie Consent requires additional rendering of the piece of content on the user’s screen - above the fold. This message can be annoying for visitors - but this is another story…

One of many goals in the publisher’s ecosystem is to achieve the best possible score of core-web-vitals. These have primary and secondary effects on websites.

  • Better score = higher CPM, because more ATF ads are viewable
  • Better score = better UX and longer time spent on the site by consuming real content
  • Better score = reduced bounce rate generated by users that are annoyed by waiting for content
  • Better score = more traffic from Google/Facebook (based on our tests)

So... showing Cookie Consent can have a significant impact on website’s revenue. So how can these issues be fixed?

In our case study we focused on modifying Cookie Consent and website to eliminate the negative effects to core-web-vitals.

After some brainstorming we asked ourselves:

Do we have to show Cookie Consent immediately when a new user visits the website? They haven’t seen our website before, they do not know what content there is and we ask for their permission to use their data anyway?

Our answer was: NO. We can give the users a critical “piece of content” and if they are interested then ask to submit their choice if they’d like to continue to consume the website’s content.

So what did we do?

The main problem with implementing our ideas is the GDPR. So we extracted all scripts that can collect any data and changed the principle of triggering these scripts.

We moved ATF units on mobile from position “after title” to the lower position - after the 1st paragraf. We achieved the immediate visibility of a more real content on ATF position.

We delayed the Cookie Consent pop-up by creating a script that triggers it only after some user’s interaction, such as:

  • Scroll
  • Mouse movement
  • Tap - on mobile
  • Click

The Cookie Consent is being triggered only after one of these actions so we are not demanding the user’s consent immediately after visiting the page. We rather give the visitor the ability to consume at least some piece of content without disturbing them with pop-ups or ATF ads.

If a user reads the title and the first paragraph and is interested in the article he starts scrolling which triggers the Cookie Consent and all the necessary scripts for ads and analytics.

What are the results?

  • We got a better core-web-vitals score because all third-party scripts are paused.
  • We got better UX because no pop-ups are showed
  • We got a better conversion rate of consents.

So we achieved our goal :)