The verdict in three sentences
In Montreal, a Core Web Vitals audit costs EUR 1,200 to 3,500 and a targeted technical rebuild EUR 4,000 to 14,000 in 2026. Moving an LCP from 4.2 s to 1.8 s improves conversion by 8 to 20 % and cuts bounce rate by 10 to 25 %. The ROI is measured in weeks, not months, once traffic is significant.
What performance costs
Web performance is fixed in tiers. You do not rebuild an entire site: you fix the items weighing on LCP, INP and CLS. Here are 2026 ranges for a mid-size Montreal B2B site.
| Service | 2026 cost (EUR) | Timeline |
|---|---|---|
| Full CWV audit + report | 1,200 - 3,500 | 1 week |
| Image / lazy-load optimization | 800 - 2,500 | 3 - 5 days |
| Front-end rebuild (SSR/edge) | 4,000 - 9,000 | 3 - 5 wks |
| Hosting / CDN migration | 1,500 - 4,000 | 1 - 2 wks |
| JS / third-party cleanup | 1,000 - 3,500 | 1 - 2 wks |
| Monitoring / month | 250 - 700 | Recurring |
A full project (audit + front-end rebuild + CDN + JS cleanup) runs EUR 8,000 - 16,000 and is enough in 90 % of cases to move all three metrics into the green.
The quantified before/after gains
Google's 2026 thresholds remain: LCP < 2.5 s, INP < 200 ms, CLS < 0.1. Here are orders of magnitude observed on B2B sites after optimization.
| Metric | Before | After | Business effect |
|---|---|---|---|
| LCP | 4.2 s | 1.8 s | +8 to +20 % conversion |
| INP | 380 ms | 140 ms | -12 % bounce |
| CLS | 0.28 | 0.04 | +5 % pages/session |
| Mobile score | 42/100 | 90/100 | Better SEO crawl |
| Organic traffic | base | +10 to +25 % / 6 months | More leads |
Google has used CWV as a ranking signal since 2021; in 2026 their weight on mobile SEO has grown. A fast site is no longer a luxury: it is a prerequisite to rank on competitive B2B queries.
Realistic timelines
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
An audit is delivered in 5 to 7 business days. A targeted technical rebuild runs 3 to 5 weeks: week 1 diagnosis and prioritization, weeks 2-3 front-end and asset optimization, week 4 CDN migration and testing, week 5 QA and measurement. Ongoing monitoring prevents regression (a new marketing script can sink the LCP in a single day).
Mini case study
Sophie, B2B e-commerce manager for a Montreal medical-equipment distributor, suffers a 4.5 s LCP and a 1.6 % conversion rate on 40,000 visits/month. Technical rebuild at EUR 11,000: LCP brought to 1.7 s, conversion up to 2.1 %. On an average cart of EUR 340, that 0.5-point gain means 200 more orders/month, i.e. EUR 68,000 additional revenue/month. The investment pays back in under a week of margin. Monitoring at EUR 450/month protects the gain.
FAQ
What does a simple audit cost? Between EUR 1,200 and 3,500 depending on site size, delivered within a week with a prioritized, costed action plan. It is the mandatory starting point before any rebuild quote.
What conversion gain to expect? Moving an LCP from over 4 s to under 2 s typically wins 8 to 20 % conversion and cuts bounce by 10 to 25 %. Gains are stronger on mobile and slow connections.
Do we need to rebuild everything? Rarely. In 70 % of cases, optimizing images, third-party JS and hosting is enough for EUR 4,000 to 8,000 without touching the design.
How long to see the SEO effect? Technical gains are immediate, but the ranking effect shows over 6 to 12 weeks after re-crawl, with +10 to +25 % organic traffic at 6 months.
Does the gain last? Only with monitoring (EUR 250 - 700/month). Without it, a new marketing tag or a poorly compressed image can sink the metrics again within 24 h.
Let's scope your project. Send us your URL and current PageSpeed scores, and we price the audit then the technical rebuild with guaranteed LCP/INP/CLS targets. 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.
