“I’ll Rank My Site by Fixing Core Web Vitals,” Said No SEO Ever

By Jason Poser and Jason Kilgore:

The world of SEO is filled with shifting trends; back in the day Matt Cutts used to describe it as “A constantly moving target”. One such shift over the past few years has been the increasing focus, and a bit of mystery, around Core Web Vitals and how impactful it is to search ranking.  We hope to unpack and demystify this. 

Introduced by Google as essential components of the Page Experience Update. These metrics—Largest Contentful Paint (LCP), Cumulative Layout Shift (CLS), and First Input Delay (FID) which recently phased out and transitioned to Interaction to Next Paint (INP)—sparked both curiosity and debate among SEOs. But let’s be clear: while optimizing Core Web Vitals is valuable for user experience, it’s not a silver bullet for rankings.

In this article, we’ll dive into:

1.           A Breakdown of Core Web Vitals and Their Purpose.

2.           Google’s Sometimes-Contradictory Statements About Their Impact on Rankings.

3.           Core Web Vitals: When They Matter, When They Don’t

4.           Conclusion

 

1. Breaking Down Core Web Vitals: LCP, CLS, and INP

What Are Core Web Vitals?

Core Web Vitals are performance metrics that quantify a website’s user experience in terms of loading speed, visual stability, and interactivity. The thresholds for each metric were set based on a combination of prominent user experience industry research along with real user web page data. Google uses these metrics to evaluate whether users can easily and comfortably navigate a site and these can be measured directly by real user data (CRUX) and can be estimated via lab data through tools like lighthouse and speed curve.

Largest Contentful Paint (LCP)

LCP measures the time it takes for the largest visible content element (e.g., hero images, headings, or blocks of text) to load and become visible in the viewport. As of this writing, based on current overall market conditions a good LCP score is under 2.5 seconds.

•              Why It Matters: A slow LCP means users are waiting longer to access the primary content, increasing the likelihood of abandonment.

•              Common Bottlenecks: Slow server response times, render-blocking resources (like CSS or JavaScript), and large media files.

•               

Cumulative Layout Shift (CLS)

CLS measures the visual stability of a webpage by tracking unexpected changes in layout (shifts) during loading or while scrolling. As of this writing, based on current overall market conditions a good CLS score is below 0.1.

•              Why It Matters: Unexpected interruptions are not a positive user experience. Nobody enjoys having an interstitial load or an ad get injected while reading content; breaks in attention at best and at worst leading to misclicks; it all adds up to frustration.

•              Common Bottlenecks: Poorly defined image dimensions, late-loading ads, and dynamically injected content.

Interaction to Next Paint (INP)

INP is the newest addition to Core Web Vitals, replacing First Input Delay (FID). It measures the latency of all user interactions (like clicks, taps, or keystrokes) and highlights the slowest interaction. As of this writing, based on current overall market conditions a good INP score is under 200 milliseconds.

•              Why It Matters: Users expect responsive websites. High interaction delays can lead to frustration and abandonment.

•              Common Bottlenecks: Long-running JavaScript tasks, unoptimized event handlers, and heavy third-party scripts.

These metrics align with Google’s goal of creating a faster, more user-friendly web. But are they a significant ranking factor or just another quality signal?

 

2. Google’s Statements: A Hint or More Than a Hint?

When Google introduced Core Web Vitals, it was pretty clear that Google was pushing the market and SEO community to adopt it. Would these metrics carry significant ranking weight, or were they more of a “nice-to-have”? Google’s messaging hasn’t always been crystal clear, adding to the confusion; even today, there is still a debate about the weighing page speed metrics carry, albeit not as controversial as “subdomains vs subfolders”.

Google’s Official Line: Core Web Vitals as a Ranking Signal

Google announced (in 2020) that Core Web Vitals would become part of the Page Experience update in 2021, combining with other signals like HTTPS, mobile-friendliness, and safe browsing. The search giant, which persistently maintains nearly 90% US search engine market share, emphasized that these metrics are ranking signals, but they also repeatedly described them as “lightweight” compared to more traditional signals like relevance, content quality, and backlinks.

•              “A Tiebreaker”: Google likened Core Web Vitals to a tiebreaker for ranking decisions. If two sites are equally matched in content quality and backlinks, the one with better Core Web Vitals might edge ahead.

•              User Experience Focus: Google has consistently framed Core Web Vitals as part of a broader initiative to enhance user experience rather than a direct path to higher rankings.

Mixed Messages from Google

Despite these official statements, various Google representatives have offered differing takes:

1.           “Helpful, But Not Decisive”: John Mueller, a Google Search Advocate, often downplays the ranking impact of Core Web Vitals. He’s noted that sites can still rank well with poor Core Web Vitals if their content and relevance are strong.

2.           Case Studies Suggest Otherwise: Some SEOs have shared anecdotes of improved rankings after Core Web Vitals optimizations, but these cases often include simultaneous improvements to content and technical SEO—making it hard to isolate the impact.

3.           Emphasis on Holistic Value: Google frequently reminds webmasters that Core Web Vitals are just one part of a larger picture. High-quality content, user intent, and link authority remain at the forefront of ranking success.

 

This mixed messaging has left many SEOs wondering: are Core Web Vitals worth the investment for rankings.

3. Core Web Vitals: When They Matter, When They Don’t

While it’s tempting to dismiss Core Web Vitals as “a minor ranking factor of the ever growing number of them,” doing so overlooks the real value of these metrics. Beyond their lightweight (if even present) impact on search rankings, Core Web Vitals absolutely promotes a better user experience. This section explores why these metrics deserve attention—not because they’re a magic ticket to SEO success, but because they directly influence how users interact with and perceive your website.

User Experience: Be Unobtrusively Helpful

At their core (see what I did there?), Core Web Vitals focus on improving user experience. Every aspect of these metrics addresses pain points that frustrate users regardless of what site they are on and can drive them away to consume competing content.

The Connection Between Experience and Metrics

Outperforming Core Web Vitals on a relative basis against underperforming pages almost always correlate with longer dwell times, higher engagement, and increased content consumption. Here’s how:

1.           Reduced Friction: When a site loads quickly, doesn’t shift around unexpectedly, and responds promptly to user input, visitors encounter fewer barriers to accessing the content they came for. This seamless experience makes them more likely to stick around and explore further.

2.           Positive First Impressions: The first few seconds of a user’s visit are crucial. If they experience delays, instability, or unresponsiveness, their perception of the site (and the brand) can be irreparably harmed. Core Web Vitals ensure that these first impressions are favorable.

3.           Encouraged Exploration: Users who trust the site’s stability and responsiveness are more likely to click on links, watch embedded media, or read additional articles. This increases the time they spend on the site, giving content creators more opportunities to deliver value and build loyalty.

 

Many case studies have shown improvements in Core Web Vitals metrics leading to improved user engagement and conversion rates.

 

How This Can Actually Help You Rank: The Indirect SEO Benefits of Core Web Vitals

Although Core Web Vitals are, at best, “a hint”, they can have indirect effects on SEO by improving behavioral signals and metrics that Google keeps track of.  Earlier this year, in the leaked Google Search API repository, which Michael King and Rand Fishkin covered in depth, several metrics were noted as part of that repository.  For the purposes of this article, a few are worth highlighting:

•              goodClicks: Indicates positive user interactions with search results.

•              badClicks: Represents negative user interactions, such as quick returns to the search page.

•              lastLongestClicks: Tracks the most recent and longest user engagements with a page.

•              unsquashedClicks: Refers to unfiltered or raw click data.

 

Finally, for the above metrics 13 months of click data on a page and site specific basis are used to influence that page (or site) ranking in results based on searcher context.  These metrics underscore Google’s emphasis on satisfying user experiences after they click through to your website, and promoting content which they believe algorithmically will give the solution to the problem or question which prompted the search AND does so unobtrusively.

 

4. Conclusion: A Complement, Not a Strategy

·         Optimal Core Web Vitals is undeniably important for user experience.

·         Resolving CWV issues contributes to higher user satisfaction, which can indirectly impact SEO through metrics like reduced bounce rates and increased dwell time.

·         Improved CWV can also yield real improvements in business outcomes and revenue by users being able to unobtrusively do the things on your site you want them to do.

·         A healthy appreciation of the precise source of value for users and your business should inform your decisions on whether and the extent to which you focus on CWV; not short-term rankings boosts in search

SEO success continues to rest on the fundamental principles of adding value to the world wide web content ecosystem and building authoritative links. Core Web Vitals should not be seen as an alternative strategy, but mutually reinforcing other SEO enhancements.

So, should you happen to hear a suggestion that Core Web Vitals are the key to an SEO success story, remind them: “I’ll rank my site by fixing Core Web Vitals”—said no SEO ever.