Mobile Website Speed on 3G: Why Every Second Counts in Senegal

The myth of the site "that works fine on my laptop"

Your website runs perfectly on your MacBook hooked up to fiber. Good news. Bad news: that's not how 78% of your Senegalese visitors actually access your site.

In Senegal in 2026, over 60% of mobile connections are 3G or on degraded networks. Orange, Free, and Expresso compete for 4G/5G coverage in central Dakar, but the moment you step outside the capital — or even inside buildings in Plateau, Mermoz, or Ouakam — speeds drop. Add the regions: Thiès, Saint-Louis, Kaolack, Ziguinchor. For diaspora visitors checking your site over patchy hotel Wi-Fi or a phone roaming on a local SIM, the experience is often worse.

If your site takes more than 3 seconds to load on 3G, 40% of visitors leave before even seeing your offer. Source: Google Research plus field studies in West Africa.

Core Web Vitals: the 3 metrics that really matter

Google ranks sites based on three key metrics, grouped under the name Core Web Vitals. They aren't just "technical" — they are now a direct SEO ranking factor.

1. LCP (Largest Contentful Paint) — target under 2.5 seconds

This is the time before the main content (hero image, title) appears. On Senegalese 3G, an LCP of 4-5 seconds is catastrophic. Kolonell target: under 2.5 seconds.

2. INP (Interaction to Next Paint) — target under 200 ms

This is the delay between a user action (click, tap) and the visible response. An INP of 500 ms on a "Book now" button equals a frustrated customer who leaves.

3. CLS (Cumulative Layout Shift) — target under 0.1

If your page "jumps" while loading (images arrive and push text down), users tap in the wrong place. Frustration, bounce, and a loss of trust.

7 levers to accelerate your site for Senegal

Lever 1: host close to your users

A server in Paris or Frankfurt adds 80-120 ms of baseline latency from Dakar. A CDN with edge nodes in Lagos or Cape Town brings it down to 20-40 ms. Kolonell deploys on Vercel, Cloudflare, or OVH with CDN enabled — the difference is immediate.

Lever 2: images in WebP and AVIF, not heavy PNG/JPG

An 800 KB PNG equals 2 seconds of download on 3G. The same image in WebP is 150 KB; in AVIF, 80 KB. Kolonell automatically generates all three formats and serves the one the browser supports.

Lever 3: lazy loading everywhere

Why load all 20 photos of your gallery if the visitor only sees the first 3? Lazy loading loads images only when they enter the viewport. Benefit: 60% data saved on first load — critical for diaspora visitors on mobile data.

Lever 4: optimised web fonts

Three unoptimised Google Fonts equal 400 KB and 3 blocking requests. Solution: subsetting (load only the characters you use), font-display: swap, self-hosting. Kolonell typically cuts this line item to 80 KB.

Lever 5: JavaScript split per route

An 800 KB JavaScript bundle slows the whole page. Next.js 14 (our stack) automatically splits JS per route: each page loads only the code it needs.

Lever 6: aggressive caching

Static files (images, CSS, JS) almost never change. A 1-year cache with hashed URLs makes the second visit instantaneous.

Lever 7: measure, don't guess

Google PageSpeed Insights, WebPageTest with "fast 3G" throttling, Lighthouse — these tools test in real Senegal-like conditions. A mobile score above 90 is achievable. Below 70 means you're losing customers.

Case study: from 4 seconds to 1.2 seconds

A Dakar restaurant hired us for a website redesign. Initial mobile PageSpeed score: 38/100. LCP: 4.2 seconds. After optimisation (WebP, lazy loading, Cloudflare CDN, JS cleanup): score 94/100, LCP at 1.2 seconds.

Result: +35% click-through rate on the "Reserve" button, -42% bounce rate.

The quick test to run tonight

Open your site on your phone, off Wi-Fi, on 3G. Time how long it takes before you can interact. Over 3 seconds? You're losing 40% of your visitors every day.

At Kolonell, every site we ship passes a full PageSpeed and real-world 3G battery of tests before going live. Request a quick free audit.