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In short: Core Web Vitals are three user-experience metrics: LCP (loading of main content), INP (responsiveness) and CLS (layout stability). Good values: LCP under 2.5 s, INP under 200 ms, CLS under 0.1 for 75% of visits.
What are Core Web Vitals?
A set of Google metrics measuring real visitor experience on a page. They feed into page experience signals. Speed alone won't lift weak content to the top, but a slow site loses both rankings and leads.
Which values are considered good?
| Metric | What it measures | Good |
|---|---|---|
| LCP | Time to render the largest element | ≤ 2.5 s |
| INP | Delay in responding to interactions | ≤ 200 ms |
| CLS | Layout shift during loading | ≤ 0.1 |
INP replaced FID in 2024. Pages are assessed at the 75th percentile of real-user data (CrUX), not just a lab test.
How do you improve LCP?
- Compress the main image and serve WebP/AVIF at the right size.
- Add
fetchpriority="high"to the hero image and don't lazy-load it. - Reduce server response time: page cache, current PHP version, CDN.
- Remove render-blocking CSS and JS; inline critical CSS.
How do you improve INP?
- Break up long JavaScript tasks and defer third-party scripts (chats, widgets, pixels).
- Remove unnecessary plugins and libraries.
- Avoid heavy handlers on every click or scroll.
How do you improve CLS?
- Set
widthandheighton images and video. - Reserve space for banners, cookie bars and ads.
- Use
font-display: swapand preload fonts.
How do you check your numbers?
PageSpeed Insights shows both field and lab data. The Core Web Vitals report in Search Console groups problem URLs by page type, so fix the template, not a single page. After changes, data updates over roughly 28 days.
What is specific to MODX, WordPress and Laravel?
- MODX: cache chunks and snippets, minify and combine assets, optimise images server-side.
- WordPress: remove surplus plugins, use a cache plugin, lazy loading and a lightweight theme.
- Laravel: response caching, queues, modern image formats, Vite for builds.
FAQ
Does site speed affect rankings?
Yes, as one of many signals. It affects conversion even more: slow pages lose visitors.
What PageSpeed score is enough?
Don't chase the score; aim to pass the LCP, INP and CLS thresholds in real-user data.
What should you fix first?
The worst metrics on your highest-traffic templates: homepage, categories, product or service pages.
Site feels slow and you don't know why? Get a free Kyivan audit — a developer will locate bottlenecks and name specific fixes.
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