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James Carr

With the Core Web Vitals update about to be put in place we ran a webinar covering off the key areas of change you can expect to see from next month. The webinar brought up some really great questions from some of our attendees so we wanted to share with you the most commonly asked questions…

Do PDFs negatively affect CWV?

Whether PDFs negatively affect Core Web Vitals largely depends on how the PDF is being used. If the PDF is a stand alone document that opens within its own URL, this is treated as an asset and the Core Web Vitals metrics won’t apply.

However, if a PDF is being dynamically inserted into a page (i.e. using an iframe to create a live online catalogue), this functionality could be a source of poor results for Largest Contentful Paint and Cumulative Layout Shift.

Does the LCP, FLD and CLS rating apply for all pages or is more weight given to the homepage?

The Core Web Vitals ratings apply to all pages on your site individually, with no evidence that more weight is given to your homepage. When we consider the typical Google search, emphasis is placed on the landing page that the search is relevant to, which makes sense for delivering a great user experience.

It therefore follows that landing pages will be judged on their own merit when considered for ranking, and that the score of the home page will be largely ignored (except for in searches where it is a relevant result).

What effect does user location have?

In terms of Core Web Vitals overall, user location is likely to have very little effect on the data that you’re able to gather from Google Search Console. This is because the data that determines whether your site passes is collated from real user data. If your site receives the majority of its traffic from a single location, it’s highly likely that your site won’t be affected by data from other locations.

However, if your site receives traffic from a number of different locations and your aggregated data shows that improvements could be made to your site, you may need to investigate your site performance within these locations to identify if there are any locations demonstrating slower load performance. Implementing a CDN to serve this location should help to improve site performance and user experience within that area.

When does the update kick in? Will it be a slow roll in?

The update was originally stated to start being rolled out during May 2021. However, Google has now confirmed that they intend to delay this roll out until mid-June. Google has also confirmed that the rollout will be gradual, and will not be expected to finish until the end of August 2021.

What are your thoughts on GTXmetrics for looking at Web Core Vitals along with Pagespeed insights & Search Console?

As the Core Web Vitals update is being rolled out by Google, we tend to focus on the data supplied by Google tools such as Pagespeed Insights and Google Search Console. As Google has access to this data first hand, it is likely to be much more accurate than the data supplied by other tools such as GTMetrix.

Can we only do this for sites we own?

You can check any URL for Core Web Vitals performance using PageSpeed Insights, so you can easily check your search competitors to see how the performance of your site compares.

Should images be uploaded as png and not jpeg?

Generally speaking, images using the jpeg file format demonstrate smaller file sizes and can be more effectively compressed, meaning that they tend to be a strong choice for use on websites. The main reason for using png images would be when you need to make use of the transparent background offered by this format, so it would still be a relevant choice for scenarios where that functionality is needed.

If possible, you should start investigating whether you can convert your images to next generation formats such as webp instead. These newer file formats offer even better compression and quality when compared to png and jpeg files, so should be used wherever possible. There are a number of plugins available for the major CMS’ (e.g. WordPress) that will automatically convert images to these formats upon upload.

Do cookie popup banners count as intrusive interstitials?

Cookie popup banners are generally treated as non-intrusive interstitials by search engines, so this shouldn’t be an area of concern. However, cookie pop up banners could be a source of cumulative layout shift depending on how they have been set up.
It’s worth investigating this by using the performance testing options via DevTools in the Google Chrome browser. If you see that your cookie pop up banner is triggering a cumulative layout shift, you may need to investigate how to reduce this to give your site the best chance of passing the Core Web Vitals.

Are automatic chat pop-ups bad practice here?

This would really depend on how the pop up affects the site. If it causes cumulative layout shift, then this would be considered bad practice against the new guidelines. However, if this issue isn’t flagged when the page loads, it shouldn’t be a problem.
However, we have seen instances where having a live chat plugin on the site has other effects on Core Web Vitals metrics, such as a large JavaScript file causing an increase in Largest Contentful Paint. It is therefore worth testing your page with your live chat turned off to see how much effect it is having on page load.

Does the pagespeed insights tool give a more accurate perspective than Lighthouse or web.dev?

While the information supplied by PageSpeed Insights probably can’t be described as “more accurate” (as the lab tests for all three tools are usually roughly the same), the benefit of using PageSpeed Insights comes from the field data.

This data is gathered from real world interactions with your website, so is incredibly valuable for working out where you need to focus your efforts. To pass each metric, 75% of sessions to the page need to meet the criteria provided, so field data can be a really useful way to determine how your site performs in the real world.

If you would like help with this process, feel free to get in contact with our team on 0845 450 2086 and we can help you get started, with plenty of time to spare until May.

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