The verdict in three sentences
If 85% of your West African visitors browse on a phone over 3G or 4G, every extra megabyte costs you prospects. A performance budget (page weight under 1 MB, AVIF images, CDN with a point of presence in West Africa) adds 400,000 to 1,200,000 FCFA (EUR 610 to 1,830) to a corporate website project. In return, the 2026 order of magnitude is a bounce rate cut from 55% to 35% and forms that actually get submitted.
Why page weight matters more in Dakar than in London
Average mobile speeds in Dakar have improved, but they vary widely by district, time of day and operator: a 4 MB page loads in 2 s on good 4G in Almadies and in 12 to 15 s on 3G in Pikine at peak hours. Data cost matters too: many prospects browse on 1 to 5 GB bundles and avoid heavy pages. A performance budget sets measurable ceilings before design even starts.
| Page element | Typical unoptimised site | Target performance budget |
|---|---|---|
| Total weight (mobile) | 3.5 to 6 MB | < 1 MB |
| Images | JPEG/PNG, 2.5 to 4 MB | AVIF/WebP, 300 to 450 KB |
| JavaScript | 900 KB to 1.5 MB | < 250 KB |
| Web fonts | 4 to 6 files, 400 KB | 1 to 2 files, < 80 KB |
| Hero video | autoplay, 5 to 10 MB | still image + play on click |
| Render time on 3G | 9 to 15 s | 2.5 to 4 s |
| Mobile bounce rate | 55% | 35% |
What optimisation costs in 2026
Optimisation is priced in work packages. For a 15 to 30 page corporate site, the total extra cost is 400,000 to 1,200,000 FCFA, on a site project of 1.5 to 4 million FCFA (EUR 2,290 to 6,100).
| Optimisation package | Content | 2026 cost (FCFA) |
|---|---|---|
| Real mobile audit | 3G/4G tests on Orange and Free, field data | 100,000 to 200,000 |
| AVIF/WebP images | Conversion, responsive sizes, lazy loading | 80,000 to 200,000 |
| JavaScript diet | Remove unused scripts, server rendering | 120,000 to 400,000 |
| West Africa CDN | Setup, caching, Dakar/Lagos/Abidjan point of presence | 50,000 to 150,000 + 10,000 to 40,000 per month |
| Fonts and critical CSS | Character subsetting, inline CSS | 50,000 to 150,000 |
| Light offline mode | Service worker, key pages cached | 0 to 100,000 |
| Total extra cost | 400,000 to 1,200,000 |
The CDN is often the most underrated lever: a site hosted in London with no African point of presence adds 120 to 200 ms of latency to every request, multiplied by the 40 to 80 requests on a page.
How to write the budget into the brief
Put the ceilings in the contract: maximum weight per template, LCP under 2.5 s measured on an entry-level Android phone over 4G, maximum number of third-party scripts. Require acceptance testing on a real device in Dakar, not only a Lighthouse score run from Europe. Plan a quarterly check, because every new banner or video can blow the budget.
Mini case study
David, sales director of a London IT services firm opening a Dakar office, gets 6,000 visits a month from West Africa, 85% on mobile. Bounce rate is 55% and he receives 30 quote requests a month. He invests 750,000 FCFA (EUR 1,145) in optimisation and 25,000 FCFA a month for the CDN. Bounce drops to 36%, visitors reading a second page rise from 2,700 to 3,840, and quote requests climb to 42 a month. With a 10% close rate and an average contract of 1,500,000 FCFA (EUR 2,290), the 12 extra requests are worth about 1,800,000 FCFA (EUR 2,745) in monthly revenue. The investment pays back in the first month.
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FAQ
What page weight should we target for West African visitors?
Under 1 MB on mobile for key pages. Above 2 MB, render time often exceeds 6 s on 3G.
How much does mobile optimisation of a corporate site cost in Senegal?
Between 400,000 and 1,200,000 FCFA (EUR 610 to 1,830) in 2026 for 15 to 30 pages, plus 10,000 to 40,000 FCFA a month for the CDN.
Is AVIF supported on phones used in Senegal?
Yes on the vast majority of recent Android browsers. A WebP or JPEG fallback covers the 5 to 8% of older devices.
Should the site be hosted in Senegal?
Not necessarily. European hosting with a CDN that has a West African point of presence cuts latency by 120 to 200 ms per request at moderate cost.
What bounce rate improvement can we expect?
The observed order of magnitude is a drop from 55% to 35%, about a third fewer visitors leaving without interacting.
Let's scope your project. We set your site's performance budget, 400,000 to 1,200,000 FCFA (EUR 610 to 1,830) depending on page count, with real-device acceptance testing in Dakar within 2 to 4 weeks. Detailed quote within 48 h. 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.
