TLDR
- Google measures real user experience via three metrics: LCP (load speed), INP (responsiveness), CLS (visual stability).
- Google uses actual visitor data (CrUX), not one-time lab tests, and requires 75% of real visits to pass “good” thresholds.
- Core Web Vitals are a ranking tiebreaker, not the top-priority factor — but they compound with engagement and conversion benefits.
- Most performance problems stem from a handful of small, fixable issues (images, bloated themes, ads) rather than one big flaw.
There was a time when SEO largely dealt with keywords and backlinks. Today, how a site feels to use matters just as much to Google. Pages that take a long time to load or are slow and lag when someone taps a button cause site visitors to leave and go to the competition. Google’s algorithms notice this, and it negatively affects a site’s rankings. That’s where Core Web Vitals come in.
Google built Core Web Vitals to assess actual user experience as opposed to service provider guesses. They are a real part of how sites are evaluated, and if you choose to ignore them, you are conceding to the competition.
When similar quality content is available on different sites, the site that performs better is the site that wins the race. Core Web Vitals are the reason this happens, and this is why everyone from the site owner to developers and SEO specialists care about Core Web Vitals.
How Core Web Vitals Are Measured
As of 2024, Core Web Vitals consist of three metrics: Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift.
- Largest Contentful Paint (LCP) measures the loading of the primary content on the page, typically the largest heading, image, or block of text above the fold. According to Google, a “good” LCP is achieved in less than 2.5 seconds. Each additional second it takes a visitor to view the page’s banner or heading creates the perception of slow loading on the rest of the page that remains empty.
- Interaction to Next Paint (INP) is the measurement of a page’s response to interaction, both input and visual response. It includes the first input (or click) as well as additional interactions. Google’s benchmark is set under 200 milliseconds. A web page that continually lags and freezes during many user inputs is an irritatingly slow experience for all visitors.
- Cumulative Layout Shift (CLS) is the measurement of how much a page’s layout shifts unpredictably while loading. It is especially annoying if a button or link is about to be interacted with and shifts position at the last moment, resulting in a clickable area on the page that is nowhere near the intended target. Google’s standard is set under a CLS score of 0.1.
Core Web Vitals at a Glance
| Metric | What It Measures | Google’s “Good” Threshold |
| LCP (Largest Contentful Paint) | Loading of the primary content on the page — typically the largest heading, image, or block of text above the fold | Under 2.5 seconds |
| INP (Interaction to Next Paint) | A page’s response to interaction, including the first click and additional interactions | Under 200 milliseconds |
| CLS (Cumulative Layout Shift) | How much a page’s layout shifts unpredictably while it loads | Under 0.1 |
The three metrics together help to provide the complete picture on how smooth a site’s experience is, versus how much it frustrates its users.
How Google Treats These Metrics
Most articles focus heavily on explaining what these metrics are, as if that’s the most important part. It isn’t.
What matters more is how Google actually uses this data. Google does not run an isolated test a single time and simply move on from there. Google uses real visit data, which is collected through the Chrome User Experience Report (CrUX). A page is only considered to be “good” if at least 75% of real visits meet all 3 metrics. This is actually a very challenging benchmark since it means that the majority of the real traffic, not a best-case estimate, needs to meet the threshold.
It is also useful to know that Google evaluates this at the page level rather than at the level of the site as a whole. You can have pages that perform very well, and others that perform very poorly, and each is judged individually as opposed to averaging the site as a whole.
Do Core Web Vitals Affect Rankings?
The short answer is yes, but it is important to qualify the answer.
These metrics were introduced into Google’s ranking systems as part of the 2021 Page Experience update. They are not seen as the highest priority ranking factors. However, they can be a legitimate tiebreaker. For example, both websites score highly for quality and relevance; however, the website that scores better for Core Web Vitals will be ranked higher.
This has been confirmed by research done outside of Google. One example is DebugBear. The pages in the number one position on Google had a much higher Core Web Vitals pass rate when compared to pages in the ninth position on Google. This does not definitively show that Core Web Vitals are the sole ranking factor. However, this is a measurable pattern that shows up in actual search results.
In areas that are quite competitive with many websites offering similar services, like any other ranking factor, Core Web Vitals will likely determine the difference between being ranked on the first page of search results and the second page of search results.
The Real Business Impact, Beyond Just Rankings
Beyond ranking, Core Web Vitals improvements tend to boost other business metrics too. There are numerous reports showing that an improvement in Core Web Vitals also results in an improvement of user engagement.
A page with better loading and stable performance is likely to:
- Have users spend more time on the page rather than returning to the search results page
- Satisfy users, increasing the credibility of a site in users’ eyes
- Convert more users into paying customers rather than losing them before they buy
None of this is required for a page to rank — but each of these outcomes feeds into engagement signals that Google’s ranking systems do take into account. A better performing site will rank higher and bring in higher quality visitors.
How to Check Your Core Web Vitals
Knowing where your site ranks is the first step in improving. Some tools that cover this are:
- Google PageSpeed Insights – provides real world data in the form of CrUX and provides recommendations
- Google Search Console Core Web Vitals – this tool indicates which of your pages have passed or failed, along with the issue
- Lighthouse – a deeper technical review for developers
- Chrome User Experience Report (CrUX) – provides the real-user dataset that Google uses to rank pages
Doing this on a regular basis will give you a better idea of your site’s performance. A site that passes today can slip in a few months because of a marketing script, a theme update, or a plugin update.
Practical Solutions to Improve Each Metric
Most issues with Core Web Vitals boil down to a few common problems that are usually easy to resolve.
For LCP:
- Optimize images to reduce their size.
- Move to better rated hosting and enable site level caching.
- Preload important images and fonts so they load asynchronously.
For INP:
- Reduce unneeded JavaScript which delays the page’s interaction with the user.
- Break large scripts into several to allow the browser to work on several tasks instead of idly waiting on one to finish.
- Remove or postpone non-critical page operating scripts.
For CLS:
- Specify height and width of images, videos, and ads so the browser knows where to place each resource.
- Use font-display so the browser doesn’t move text around as custom fonts load.
- Reserve space for embeds and ads.
Core Web Vitals problems are rarely caused by one large issue. More often, they snowball from a handful of smaller issues.
Most Common Issues That Hurt Performance
These common problems are found on many sites that have issues with Core Web Vitals:
- Heavy sliders, carousels, and animations that don’t contribute much but add heavy code to the site.
- Too many ads that use up a lot of the site bandwidth and distract the users.
- Under-resourced or cheap hosting that can’t handle real traffic.
- Using a poorly designed theme that includes a lot of useless code.
- Large, unoptimized photos and videos that were never compressed.
Cleaning up these issues will not only improve your Core Web Vitals scores, but will also improve the actual user experience of your website.
Where This Is Heading
Google’s focus on real user experience isn’t a passing phase — it’s becoming more central to how sites are evaluated. Sites that consider performance a nice-to-have will continue to lose to sites that focus on performance, even if their content is equally strong.
Site performance and real user experience should be looked at as equal priorities. A site that is high performing in real user experience but poorly performing in content is only doing half the job.
Frequently Asked Questions
What are Core Web Vitals?
These are the metrics used by Google to measure user experience on a site: the loading speed of the page, the page’s responsiveness, and the page’s overall visual stability.
Do Core Web Vitals impact SEO rankings?
Yes, they do. Google confirmed that these factors are used in their ranking algorithms and help to determine page ranking if all other factors, like page quality, are equal among competing pages.
What has First Input Delay been replaced with?
Interaction to Next Paint (INP) was introduced in March 2024 to define the processing of the entire user interaction instead of just the first click. As a result, it replaced First Input Delay.
How do I check Core Web Vitals for my site?
Google PageSpeed Insights, Google Search Console’s Core Web Vitals report, and Lighthouse are among the most common tools to evaluate Core Web Vitals.
Does having optimal Core Web Vitals matter more than quality content?
No. Publishing great content is the first and foremost initiative. A fast, optimized page will give you a huge advantage over the competition, but it doesn’t replace strong content.
What Does It All Boil Down To?
Core Web Vitals have moved from a technical consideration to a broad, confirmed element in how Google assesses and evaluates pages.
A good page will not reach its full ranking potential with poor performance, so it is imperative to optimize for performance. Treating it as ongoing work instead of a one-time undertaking will dispel the threat of performance as a ranking factor and establish it as a strong advantage.
