Quick answer: Core Web Vitals are three measures of real-user page experience: LCP (loading, good at 2.5 seconds or less), INP (responsiveness, good at 200 milliseconds or less) and CLS (visual stability, good at 0.1 or less). They are assessed at the 75th percentile of real page loads. Fix them by optimising your main image, trimming JavaScript and reserving space for images and ads.
Key takeaways
- LCP, INP and CLS replace older speed scores. INP replaced FID as the responsiveness metric in March 2024.
- Targets are measured on real-user (field) data at the 75th percentile, not only lab tests.
- Large hero images, slow hosting and render-blocking scripts are the usual LCP problems.
- Heavy JavaScript and third-party widgets hurt INP.
- Images without width and height, and late-loading banners, cause CLS.
- Fast pages help visitors convert. Do not expect speed alone to rank a weak page.
Indian visitors mostly browse on mid-range phones and mobile networks, so a heavy website loses people before it even loads. Core Web Vitals give you three numbers to measure and improve that experience.
Table of Contents
What are Core Web Vitals?
| Metric | Measures | Good |
|---|---|---|
| LCP, Largest Contentful Paint | How fast the biggest visible element (often the hero image or heading) appears | 2.5 seconds or less |
| INP, Interaction to Next Paint | How quickly the page responds to taps, clicks and key presses | 200 milliseconds or less |
| CLS, Cumulative Layout Shift | How much the layout jumps around while loading | 0.1 or less |
These targets are measured at the 75th percentile of page loads, across mobile and desktop. In practice, three out of four of your visitors should get a good experience. INP replaced the older First Input Delay (FID) metric in March 2024.
How do you measure them?
- Google Search Console: the Core Web Vitals report groups URLs as good, needs improvement or poor, using real-user data.
- PageSpeed Insights: shows field data (if your site has enough traffic) plus a lab test with specific fixes.
- Chrome DevTools and Lighthouse: useful for debugging, but lab results can differ from what visitors experience.
Always test the mobile result first. Small sites may not have enough traffic for field data, so use lab tests to find problems and check Search Console over time.
How do you fix a slow LCP?
- Compress and resize images. Do not serve a 3,000-pixel photo in a 400-pixel space. Use WebP or AVIF where possible.
- Do not lazy-load the hero image. Lazy-load images below the fold only.
- Preload the main image if it is a CSS background or discovered late.
- Improve hosting response time. A slow server delays everything. Use caching and a CDN.
- Remove render-blocking CSS and JavaScript. Inline critical CSS or load scripts with defer.
- Self-host or limit fonts. Load only the weights you use.
How do you improve INP?
- Remove unused plugins, widgets and tracking scripts. Each one adds JavaScript that competes with user taps.
- Load chat widgets, heatmaps and ad scripts after the page is interactive.
- Break up long JavaScript tasks so the browser can respond between them.
- Keep menus, accordions and forms light. Avoid heavy animation on tap.
How do you stop layout shifts?
- Add width and height (or an aspect ratio) to every image and video.
- Reserve space for banners, cookie notices and ads so they do not push content down.
- Use font-display settings and similar fallback fonts to avoid text jumping.
- Avoid inserting content above existing content after load.
What did we change on our own site?
On bafnadigitechsolution.com we replaced the Tailwind CSS development script, which builds styles in the visitor's browser, with a compiled stylesheet, and removed a blocking font import from our CSS. Changes like these cut render-blocking work. Your results depend on your own site, hosting and content, so measure before and after.
Our website speed optimisation guide goes deeper on caching, images and hosting, and our website development service builds fast sites from the start.
Will better Core Web Vitals improve rankings?
They are part of Google's page experience signals, but a fast page does not outrank a more helpful one. Treat speed as a way to keep visitors and improve conversions, alongside strong content and technical SEO.
Frequently Asked Questions
What are the Core Web Vitals thresholds?
LCP should be 2.5 seconds or less, INP 200 milliseconds or less and CLS 0.1 or less, measured at the 75th percentile of real page loads.
What replaced First Input Delay?
Interaction to Next Paint (INP) replaced First Input Delay as a Core Web Vital in March 2024.
Where can I see my Core Web Vitals?
In Google Search Console's Core Web Vitals report and in PageSpeed Insights, which shows real-user data when available and a lab test with suggestions.
Why is my score good in a lab test but poor in Search Console?
Lab tests run on one device and network. Search Console uses real visitors on many devices and connections, which is what counts.
Do Core Web Vitals affect SEO?
They are part of Google's page experience signals, but content quality and relevance matter more. Good speed mainly helps visitors stay and convert.
Can you improve my website speed?
Yes. We audit images, hosting, scripts and layout issues and fix them. Contact us for a speed review.
Sources and further reading
- web.dev: Web Vitals
- Google PageSpeed Insights
- Specification.website: Core Web Vitals summary of thresholds
Thresholds are taken from web.dev guidance and may be updated by Google. Re-check before major decisions.