The verdict in three sentences
A slow B2B site loses leads silently: every extra second of load time costs between 7 and 12% of conversion. Optimizing Core Web Vitals (LCP < 2.5s, INP < 200ms, CLS < 0.1) costs $3,500 to $10,000 in 2026 and returns +10 to +25% conversion. For a firm in Singapore with existing traffic, it's the highest-ROI optimization before you spend a single dollar on acquisition.
The 3 metrics that drive conversion
Since INP replaced FID, Google measures the real responsiveness of your pages. Here are the 2026 thresholds and their business impact.
| Metric | Good | Needs work | Poor | Main impact |
|---|---|---|---|---|
| LCP (loading) | < 2.5s | 2.5 - 4s | > 4s | First impression, bounce |
| INP (responsiveness) | < 200ms | 200 - 500ms | > 500ms | Frustration, form abandonment |
| CLS (stability) | < 0.1 | 0.1 - 0.25 | > 0.25 | Misclicks, trust |
A site failing all three stacks lost SEO rankings and lost conversion: the double negative.
Before / after: what an optimization changes
Here is a typical optimization on a heavy WordPress B2B site migrated to a modern stack (Next.js + edge CDN).
| Indicator | Before | After | Gain |
|---|---|---|---|
| LCP | 4.2s | 1.8s | -57% |
| INP | 480ms | 140ms | -71% |
| CLS | 0.28 | 0.04 | -86% |
| Bounce rate | 62% | 41% | -21 pts |
| Conversion rate | 1.9% | 2.4% | +26% |
| Pages/session | 2.1 | 3.3 | +57% |
Cost structure and hosting 2026
| Line item | 2026 range |
|---|---|
| Performance audit | $1,400 - $4,000 |
| LCP/INP/CLS optimization | $3,500 - $10,000 |
| Migration to Next.js/CDN | $9,000 - $28,000 |
| Edge hosting (global CDN) | $35 - $140/month |
| Continuous monitoring (RUM) | $25 - $90/month |
Moving to edge hosting (content served from a node near the user) is often the most cost-effective LCP lever: a few dozen dollars/month for a gain of several hundred milliseconds.
Mini case study
Wei Lin is head of marketing at an industrial firm in Singapore. Her site draws 18,000 visits/month at a 1.9% conversion rate, i.e. 342 leads. Average commercial deal: $7,000, closing rate 8%.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
She invests $7,000 in a Core Web Vitals optimization. Conversion rises to 2.4% (+26%), i.e. 432 leads/month, +90 leads. At 8% closing and a $7,000 deal, that's 7.2 additional clients/month, i.e. $50,400 in extra monthly revenue. Payback is reached in under two weeks of production.
FAQ
What conversion gain should I expect from a Core Web Vitals optimization?
Between +10 and +25% on average for a site starting from a poor score. The gain peaks when LCP drops below 2.5s and INP below 200ms at the same time.
Do I have to migrate to Next.js?
No. A WordPress site can hit good scores with caching, optimized images and a CDN for $3,500-7,000. Migration ($9,000-28,000) is warranted when technical debt is heavy or you target 2-4x gains.
How much does edge hosting cost in 2026?
From $35 to $140/month for an SME, depending on traffic. It's often the best cost/gain ratio on LCP, before touching a line of code.
How do I measure the real impact on my business?
With RUM (Real User Monitoring, $25-90/month) paired with your analytics: you correlate visitors' actual speed with their conversion rate, page by page.
How fast do results show up?
Conversion gains are immediate at deployment. SEO gains tied to Core Web Vitals take 4-8 weeks to reflect in rankings.
Let's scope your project. Send us the URL to audit, your monthly traffic and current conversion rate, and we'll price the optimization and project the lead gain. 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.
