The verdict in three sentences
Core Web Vitals are the three grades Google gives your visitors' real experience: render speed (LCP < 2.5 s), click responsiveness (INP < 200 ms) and visual stability (CLS < 0.1). Moving from red to green improves both your SEO ranking and your conversion rate, without touching the content. Three areas account for 90 % of the fixes: images, JavaScript and fonts.
Red vs green: what Google actually measures
Unlike old speed scores, Core Web Vitals measure the experience of real users (Chrome CrUX data). Here is the official 2026 grid.
| Metric | Good (green) | Needs improvement | Poor (red) |
|---|---|---|---|
| LCP — main render | < 2.5 s | 2.5 to 4 s | > 4 s |
| INP — click responsiveness | < 200 ms | 200 to 500 ms | > 500 ms |
| CLS — visual stability | < 0.1 | 0.1 to 0.25 | > 0.25 |
LCP measures when the largest visible element appears (often a banner image). INP measures the delay between a click and the site's reaction. CLS penalizes pages that "jump" during load, when an ad or image pushes text further down.
Priority fixes, from most profitable to least urgent
No need to do it all at once. Attack the areas that weigh most.
| Priority | Common problem | Fix | Metric gained |
|---|---|---|---|
| 1 | Heavy uncompressed images | WebP + lazy-load | LCP |
| 2 | Blocking marketing JavaScript | Defer / remove | INP |
| 3 | Web fonts blocking render | Preload + font-display swap | LCP |
| 4 | Images without fixed dimensions | Reserve size upfront | CLS |
| 5 | Banners and ads that shift layout | Reserved slots | CLS |
| 6 | Distant, slow server | CDN + cache | LCP / TTFB |
The tools are free: PageSpeed Insights for an instant diagnosis, and the CrUX report to see your scores over 28 days of real traffic. Measure, fix, re-measure.
Mini case study
Ibrahim runs an accounting firm in Thiès. His site showed a 5.8 s LCP (red), a 420 ms INP (needs improvement) and a 0.32 CLS (red, caused by a banner shifting the menu). The audit cost 150,000 FCFA. Three fixes were enough: WebP banner with fixed dimensions, removal of two useless tracking scripts, preloading the heading font. Result: LCP 2.2 s, INP 180 ms, CLS 0.05, all three green. Within six weeks his site moved from page 2 to position 4 on "accountant Thiès", and contact requests doubled from 4 to 9 per month.
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FAQ
Do I need to be a developer to fix Core Web Vitals?
No for the diagnosis: PageSpeed Insights is free and readable. For the fixes, a provider usually handles them in 2 to 5 days. A full audit ranges from 100,000 to 200,000 FCFA in 2026.
Does a poor score really cost me rankings?
Yes. With equivalent content, Google favors the page offering the better experience. CLS and LCP weigh especially on mobile, where over 80 % of Senegalese traffic happens.
Which metric should I fix first?
LCP in most cases, since it depends mostly on images, which are easy to lighten. CLS often comes right after because it is solved by fixing element dimensions, a quick job.
My scores change from one test to another, is that normal?
Yes. PageSpeed gives a one-off lab measurement. The data that matters for ranking is CrUX, averaged over 28 days of real visitors. Trust that trend, not an isolated test.
How long before I see the SEO effect?
Budget 4 to 8 weeks: Google must re-crawl your pages and absorb the new CrUX data. The conversion gain, however, is immediate at launch.
Let's talk about your project. We send you your annotated Core Web Vitals report, then a quoted fix plan. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
