The most common Web Vitals issues and how to fix them
Posted: Sun Jan 05, 2025 10:41 am
On average, a desktop page with a "bad" TBT score has 6 times more long tasks compared to those in the "good" range. On mobile, this difference is more modest: it triples.
What affects CLS scores
The CLS metric, which measures the visual stability of the page, relies heavily on layout shifts that appear whenever there is a change in position of a visible element from one rendered frame to the next.
As with TBT, the layout changes are more about scope than the number of those changes. And if we didn't see direct evidence of this with TBT, our CLS analysis makes it clear:
We don't see a huge difference in the number of layout changes between pages with different CLS scores, which means you can afford to have quite a few changes as long as they meet the thresholds.
Although we have outlined the main factors that affect CWV scores of pages, that does not mean that they can be considered the most pressing issues for website owners.
This is where Site Audit’s Core Web Vitals report cambodia phone number database comes in, helping you identify the most difficult checks to pass.
The Site Audit tool puts any page through 23 different checks that take into account Pagespeed Insights logic:
If the check exceeds the 90 mark, the page moves to the green zone, and we consider that this audit has been passed;
The 50-89 mark makes the page enter the yellow zone; and
If the value is less than 49, the page moves to the red zone for a given control.
Auditing your website can be easy
with Semrush Site Audit
Enter your domain
Audit your website →
ADS illustration
At a glance, we can see that mobile pages face a much higher number of CWV issues. Desktop URLs seem to be doing a good job of passing CWV checks, with the majority – 68% – of checks falling into the green dot.
Unlike on desktop, where pages passed the majority of checks, on mobile, only 34% of checks are green. A worrying 65% of all audits are yellow or red, meaning mobile pages do not meet the CWV requirements for these checks.
Let's take a more nuanced look at all the checks and see which are the three easiest and the three hardest to pass, for both mobile and desktop pages.
The top part looks almost the same whether it's a desktop or mobile URL:
Image elements that don't have explicit width and height seem to be the biggest problem on both mobile and desktop pages.
Duplicate modules in JavaScript bundles, redirects to multiple pages, and the use of video formats for effective animated content are often approved without any issues.
However, when it comes to removing render-blocking resources, the difference is striking: desktop USLs almost pass this check, while mobile USLs barely make it into the yellow zone.
Site Audit not only detects issues across all metrics, but also separates them into LCP, CLS, and OTC related issues.
What affects CLS scores
The CLS metric, which measures the visual stability of the page, relies heavily on layout shifts that appear whenever there is a change in position of a visible element from one rendered frame to the next.
As with TBT, the layout changes are more about scope than the number of those changes. And if we didn't see direct evidence of this with TBT, our CLS analysis makes it clear:
We don't see a huge difference in the number of layout changes between pages with different CLS scores, which means you can afford to have quite a few changes as long as they meet the thresholds.
Although we have outlined the main factors that affect CWV scores of pages, that does not mean that they can be considered the most pressing issues for website owners.
This is where Site Audit’s Core Web Vitals report cambodia phone number database comes in, helping you identify the most difficult checks to pass.
The Site Audit tool puts any page through 23 different checks that take into account Pagespeed Insights logic:
If the check exceeds the 90 mark, the page moves to the green zone, and we consider that this audit has been passed;
The 50-89 mark makes the page enter the yellow zone; and
If the value is less than 49, the page moves to the red zone for a given control.
Auditing your website can be easy
with Semrush Site Audit
Enter your domain
Audit your website →
ADS illustration
At a glance, we can see that mobile pages face a much higher number of CWV issues. Desktop URLs seem to be doing a good job of passing CWV checks, with the majority – 68% – of checks falling into the green dot.
Unlike on desktop, where pages passed the majority of checks, on mobile, only 34% of checks are green. A worrying 65% of all audits are yellow or red, meaning mobile pages do not meet the CWV requirements for these checks.
Let's take a more nuanced look at all the checks and see which are the three easiest and the three hardest to pass, for both mobile and desktop pages.
The top part looks almost the same whether it's a desktop or mobile URL:
Image elements that don't have explicit width and height seem to be the biggest problem on both mobile and desktop pages.
Duplicate modules in JavaScript bundles, redirects to multiple pages, and the use of video formats for effective animated content are often approved without any issues.
However, when it comes to removing render-blocking resources, the difference is striking: desktop USLs almost pass this check, while mobile USLs barely make it into the yellow zone.
Site Audit not only detects issues across all metrics, but also separates them into LCP, CLS, and OTC related issues.