Core Web Vitals Explained; Google's Key Ranking Factors in Plain English

When you're running a small business, your website is often your most valuable digital asset. You've likely invested time and resources to make it look good and showcase your products or services. But did you know that how your website performs technically can be just as important as how it looks?

Enter Core Web Vitals—Google's way of measuring whether your website provides a good experience for visitors. Unlike many of Google's mysterious ranking factors, Core Web Vitals are transparent, measurable metrics that directly impact your search rankings. And more importantly, they reflect what your actual customers experience when they visit your site.

In this post, I'll break down what Core Web Vitals are, why they matter for your small business, and how you can improve them—no computer science degree required.

What Are Core Web Vitals?

Core Web Vitals are a set of three specific measurements that Google uses to evaluate your website's overall user experience. Think of them as your website's vital signs—just like a doctor checks your heart rate, blood pressure, and temperature to assess your health.

As of 2025, the three Core Web Vitals are:

1. Largest Contentful Paint (LCP) - How quickly your page loads
2. Interaction to Next Paint (INP) - How responsive your page is
3. Cumulative Layout Shift (CLS) - How stable your page is visually

Each of these metrics measures a different aspect of user experience. Google has set specific thresholds for what it considers "good," "needs improvement," or "poor" performance for each metric.

Let's break them down in simple terms.

Largest Contentful Paint (LCP): The Speed Metric

What it measures: How long it takes for the main content of your page to load.

In plain English: How quickly can visitors see the most important stuff on your page?

Imagine walking into a store and standing there for several seconds before you can even see what products are on display. That's what a slow LCP feels like to your website visitors. The longer they wait, the more likely they are to leave.

Google considers an LCP of 2.5 seconds or faster to be good. Anything over 4 seconds is considered poor.

The Largest Contentful Paint is usually:

• Your hero image
• A large banner or slider
• A prominent headline or text block

This metric is closely related to what I discussed in my recent article "Website Speed; Why Every Second Costs You Customers," where I explored how even small delays can dramatically impact your conversion rates.

Interaction to Next Paint (INP): The Responsiveness Metric

What it measures: How quickly your website responds when a user interacts with it (clicking a button, tapping a link, etc.)

In plain English: When someone clicks on something, does your site respond immediately or does it lag?

This is the digital equivalent of speaking to a store employee who takes an awkwardly long pause before responding to your question. It creates a frustrating experience that makes visitors feel like your site is broken or sluggish.

Google considers an INP of 200 milliseconds or faster to be good. Anything over 500 milliseconds is considered poor.

Common interactions that are measured include:

• Clicking navigation menus
• Tapping buttons
• Typing in forms
• Selecting dropdown options

Cumulative Layout Shift (CLS): The Stability Metric

What it measures: How much unexpected movement occurs on your page as it loads.

In plain English: Do things jump around on your screen while the page is loading?

We've all had the frustrating experience of trying to click a button just as the page shifts, causing us to click something else entirely. This is especially problematic on mobile devices, where an unexpected shift might cause someone to tap an ad or the wrong menu item.

Google considers a CLS score of 0.1 or less to be good. Anything over 0.25 is considered poor.

Common causes of layout shifts include:

• Images or videos without defined dimensions
• Ads or embeds that load after the rest of the content
• Dynamically injected content
• Fonts that cause a flash of invisible or unstyled text

Why Core Web Vitals Matter for Your Small Business

You might be wondering, "Why should I care about these technical metrics?" Here are three compelling reasons:

1. They Directly Impact Your Search Rankings

Google has explicitly confirmed that Core Web Vitals are ranking factors. In a competitive local market, having good Core Web Vitals could give you the edge over competitors with similar content but poorer user experiences.

While content relevance is still the primary ranking factor, Core Web Vitals become the differentiator when multiple sites have similarly relevant content—which is increasingly common in local business searches.

2. They Reflect Your Customers' Actual Experience

Unlike many technical SEO factors, Core Web Vitals measure what real users actually experience when visiting your site. Google collects this data from Chrome users who have opted to share their browsing data.

This means optimizing for Core Web Vitals isn't just about pleasing Google's algorithms—it's about providing a better experience for your actual customers.

3. They Impact Your Bottom Line

Improved Core Web Vitals correlate directly with business metrics that matter:

• Better Engagement: Sites with good Core Web Vitals see 15% more page views per session and 13% longer session durations
• Lower Bounce Rates: Fast-loading pages with stable layouts keep visitors on your site
• Higher Conversion Rates: Responsive pages with minimal friction lead to more sales and inquiries

One particularly striking case study comes from Yahoo! JAPAN, which saw a 15.1% increase in page views per session and a 13.3% longer session duration after fixing their Core Web Vitals issues.

How Core Web Vitals Are Measured

Unlike many SEO factors, Core Web Vitals are based on real-world usage data—not just a single test or crawl of your website. Google collects this data through the Chrome User Experience Report (CrUX), which gathers anonymous performance metrics from actual Chrome users.

This means:

• The data reflects how your site performs for real users
• It captures performance across different devices and connection speeds
• It's based on the 75th percentile of page loads (meaning 75% of your visitors need to have a good experience)

You can view your site's Core Web Vitals data in Google Search Console, which provides a detailed report highlighting pages that need improvement.

Common Problems and How to Fix Them

Each Core Web Vital has specific issues that might cause poor performance. Here's what to look for:

Fixing Poor LCP (Slow Loading)

Poor LCP is often caused by:

1. Slow server response times - Your hosting quality matters tremendously. As I discussed in my "DIY Website Dangers" post, cheap hosting can cost you far more in lost business than you save on monthly fees.

2. Render-blocking resources - Scripts and stylesheets that prevent your page from displaying quickly.

3. Slow-loading resources - Large, unoptimized images are often the biggest culprit here.

4. Client-side rendering issues - When your website relies too heavily on JavaScript to display content.

Fixing Poor INP (Sluggish Responsiveness)

Poor INP is typically caused by:

1. Heavy JavaScript execution - Complex scripts that take too long to process.

2. Too many third-party scripts - Analytics, ads, and other external code slowing down your site.

3. Long tasks that block the main thread - When your site tries to do too much at once.

4. Inefficient event handlers - Code that doesn't respond efficiently to user interactions.

Fixing Poor CLS (Visual Instability)

Poor CLS is usually caused by:

1. Images without dimensions - Always specify width and height for images and videos.

2. Ads, embeds, and iframes without reserved space - Elements that load after the initial page load.

3. Dynamically injected content - Content that appears after the page has started rendering.

4. Web fonts causing FOIT/FOUT - Font loading that causes text to shift or flash.

How Template Websites Struggle with Core Web Vitals

It's worth noting that template-based websites often struggle with Core Web Vitals. As I explored in my article "Template Limitations: When Your Website Box Becomes a Cage," many template sites come with:

• Bloated code that slows down LCP
• Excess JavaScript that harms INP
• Layout structures prone to shifts that increase CLS

Custom-coded websites, by contrast, can be built with Core Web Vitals in mind from the ground up, ensuring optimal performance without unnecessary code bloat.

Testing Your Core Web Vitals

Want to see how your website is performing? Here are some free tools you can use:

1. Google Search Console - Provides real-world performance data for your entire site
2. PageSpeed Insights - Tests individual pages and provides specific recommendations
3. Lighthouse (in Chrome DevTools) - Offers detailed performance audits
4. Web Vitals Chrome Extension - Shows Core Web Vitals metrics as you browse your site

Remember that a single test doesn't tell the whole story. Core Web Vitals are based on actual user data collected over time, so focus on consistent improvement rather than a perfect score on a single test.

The Mobile Connection

Core Web Vitals are especially important for mobile users, who often face additional challenges:

• Slower network connections
• Less powerful devices
• Smaller screens where layout shifts are more disruptive

This ties directly into what I discussed in my article about "Mobile-First Indexing," where I explained how Google now primarily uses the mobile version of your site for indexing and ranking. Good Core Web Vitals on mobile are no longer optional—they're essential.

The Bottom Line: User Experience is Now a Ranking Factor

Core Web Vitals represent a significant shift in how Google evaluates websites. While content relevance remains king, user experience factors now play a substantial role in determining which relevant content ranks highest.

For small businesses, this is actually good news. You may not be able to compete with large corporations in terms of content volume or backlink profiles, but you can absolutely create a website that loads quickly, responds immediately, and provides a stable visual experience.

In fact, many larger corporate sites struggle with Core Web Vitals due to complex infrastructure and multiple stakeholders. This creates an opportunity for nimble small businesses to gain an edge by focusing on delivering an exceptional user experience.

Remember: when you optimize for Core Web Vitals, you're not just improving your search rankings—you're creating a better experience for your actual customers. And that's something every business should care about.

Is your website struggling with Core Web Vitals? I create clean, custom-coded websites that are built for speed, responsiveness, and stability from the ground up. Contact me at Aspire to Thrive Web Design to learn how we can improve your site's performance and search rankings.