Core Web Vitals are three essential metrics Google uses to measure the real user experience on a website. Since May 2021, these scores have directly influenced where your website ranks in search results.
If your website loads slowly, if elements jump around visually while the page loads, or if it responds sluggishly to interactions, Core Web Vitals will “drag” your score down — and Google will penalize you in the rankings.
In this guide, you'll learn what each metric means, what thresholds Google recommends, and what concrete steps you can take to improve your website's performance.
What are Core Web Vitals? — Definition
Quick definition:
Core Web Vitals are three performance metrics defined by Google — LCP (Largest Contentful Paint), INP (Interaction to Next Paint), and CLS (Cumulative Layout Shift) — that measure a web page's loading speed, responsiveness, and visual stability.
Google selected these three metrics out of dozens of performance indicators as the ones that best represent the user experience. Together, they answer three fundamental questions: how quickly does the main content appear? How fast does the page respond to interactions? And does anything visually jump around while it loads?
Since May 2021, Core Web Vitals have been part of Google's ranking algorithm as a Page Experience signal. A good score doesn't guarantee the #1 spot, but a poor score puts you at a disadvantage against competitors with similar content.
How do the 3 Core Web Vitals metrics work?
Each of the three metrics measures a different aspect of the user experience:
- LCP (Largest Contentful Paint) — measures how long it takes for the largest visible element on the screen (the hero image or main block of text) to appear. Google threshold: under 2.5 seconds = Good; 2.5-4s = Needs improvement; over 4s = Poor.
- INP (Interaction to Next Paint) — replaced FID in 2024 and measures how quickly the page responds to user interactions (clicks, key presses). Google threshold: under 200ms = Good; 200-500ms = Needs improvement; over 500ms = Poor.
- CLS (Cumulative Layout Shift) — measures how much elements visually jump around while the page loads (e.g., a button that moves just as you go to tap it). Google threshold: under 0.1 = Good; 0.1-0.25 = Needs improvement; over 0.25 = Poor.
You can check your website's scores for free using Google PageSpeed Insights (pagespeed.web.dev) or Search Console (the Core Web Vitals section). Both tools show you your current score as well as specific recommendations for improvement.
Why do Core Web Vitals matter for your business?
Key data: According to Google research, websites with an LCP under 2.5s have a 24% lower abandonment rate than those with an LCP over 4s. A user who leaves before seeing the page is a lost client.
The impact of Core Web Vitals is felt on two fronts: SEO and conversions. On the SEO front, a poor score means Google ranks you below competitors with good scores, even if your content is more relevant. On the conversion front, a slow or visually unstable page creates frustration and makes users head back to Google and choose another website.
A simple calculation: if 100 visitors a day leave because of slow speed, and 3% of them would have become clients, that means 3 clients lost every day — without your competitors lifting a finger.
Core Web Vitals and ProjectMedia's services
At ProjectMedia, Core Web Vitals are a mandatory requirement for every web design project we deliver. Every website we build is optimized to score “Good” on all three metrics, on both desktop and mobile.
The techniques we use include optimizing images and converting them to WebP, implementing lazy loading, minimizing render-blocking CSS and JavaScript, using a CDN, and configuring caching properly.
If your current website scores poorly on Core Web Vitals, we can audit and improve it without you necessarily needing a new website — a few precise technical fixes often make all the difference.
Next step:
Check your website's Core Web Vitals score for free, or contact ProjectMedia for a complete technical audit.
→ Contact ProjectMedia: office@projectmedia.ro
Frequently asked questions about Core Web Vitals (FAQ)
How do I check Core Web Vitals for my website?
The simplest way is Google PageSpeed Insights (pagespeed.web.dev) — enter your URL and you get your score and recommendations instantly, for free. Another option is Google Search Console, under the “Page Experience” section, which shows real data from your users over a 28-day period.
Do Core Web Vitals directly affect my Google ranking?
Yes, but they are one ranking signal among hundreds of others. Google has confirmed that Core Web Vitals factor into rankings as part of Page Experience. They are not the deciding factor, but if two competitors have similar content, the one with better scores has the edge. A poor score can be a significant disadvantage in competitive niches.
What Core Web Vitals score is considered good?
Google defines the “Good” threshold as LCP under 2.5 seconds, INP under 200 milliseconds, and CLS under 0.1. Hitting “Good” on all three metrics, on both mobile and desktop, is the ideal goal. Mobile is the priority, because Google uses mobile-first indexing.
What causes a poor Core Web Vitals score?
The most common causes are: unoptimized images (file sizes that are too large), render-blocking JavaScript that delays page rendering, no CDN, low-quality hosting, and third-party ads or widgets that cause layout shift. Each cause has specific technical fixes that an audit can pinpoint.
Next step:
Is your website scoring poorly on PageSpeed? The ProjectMedia team optimizes technical performance and Core Web Vitals. Request a free analysis.
→ Contact ProjectMedia: office@projectmedia.ro
Related services
Learn exactly how speed affects your Google rankings — and the concrete steps you can take to climb higher in organic search.