The verdict in three sentences
A B2B website whose Core Web Vitals stay amber in Search Console (LCP 4.1 s, INP 380 ms, CLS 0.22) loses rankings and quote requests without anyone noticing. In 2026 an audit alone costs EUR 900 to 2,500 excl. VAT (about GBP 780 to 2,150) and fixes EUR 2,500 to 9,000 depending on the CMS, over 2 to 5 weeks. The average observed gain is 15 to 30% more organic sessions within 4 months on fixed pages, provided you address root causes and not just the score.
The three metrics in plain business language
- LCP (Largest Contentful Paint): how long the main element, often the hero image, takes to appear. "Good" threshold: 2.5 s. At 4.1 s, a mobile visitor sees a blank or half-built page for 4 seconds.
- INP (Interaction to Next Paint): responsiveness when someone taps a menu or button. "Good" threshold: 200 ms. At 380 ms, the site feels frozen.
- CLS (Cumulative Layout Shift): visual stability. "Good" threshold: 0.1. At 0.22, blocks jump during loading and users tap the wrong thing.
Google measures these values on real Chrome users (CrUX data) at the 75th percentile. For a London industrial services SME, such as maintenance, fabrication or non-destructive testing, visitors often browse from a smartphone on site over average 4G: that is where the gaps are widest.
What an audit and the fixes cost
| Service | WordPress | Shopify or Wix | Custom site (Next.js, Laravel) | Timeline |
|---|---|---|---|---|
| Audit only (prioritised report) | EUR 900 to 1,800 | EUR 900 to 1,500 | EUR 1,500 to 2,500 | 3 to 5 days |
| Level 1 fixes (images, fonts, cache) | EUR 2,500 to 4,000 | EUR 2,000 to 3,500 | EUR 3,000 to 4,500 | 1 to 2 weeks |
| Level 2 fixes (third-party scripts, theme, JavaScript) | EUR 4,000 to 7,000 | EUR 3,500 to 5,500 | EUR 4,500 to 7,500 | 2 to 4 weeks |
| Full fixes with template rework | EUR 6,000 to 9,000 | Limited by the platform | EUR 6,500 to 9,000 | 3 to 5 weeks |
| Monthly metric monitoring | EUR 150 to 300 per month | EUR 150 to 250 per month | EUR 150 to 300 per month | Ongoing |
A serious audit goes beyond a PageSpeed screenshot: it combines Search Console field data, lab measurements on the 10 to 20 key templates and the list of third-party scripts (chat, analytics, tag manager, maps, video).
Fixes ranked by impact and cost
| Fix | Target metric | Indicative cost excl. VAT | Typical impact | Priority |
|---|---|---|---|---|
| AVIF or WebP images with explicit dimensions | LCP, CLS | EUR 400 to 1,200 | LCP minus 1 to 2 s | High |
| Preloading the hero image | LCP | EUR 150 to 400 | LCP minus 0.3 to 0.8 s | High |
| Self-hosted fonts, font-display swap | LCP, CLS | EUR 300 to 700 | CLS minus 0.05 to 0.1 | High |
| Deferring or removing third-party scripts | INP | EUR 600 to 2,000 | INP minus 100 to 200 ms | High |
| Server cache and CDN | LCP | EUR 300 to 900 | TTFB minus 300 to 600 ms | Medium |
| Reserved space for banners and cookie bars | CLS | EUR 200 to 600 | CLS minus 0.05 to 0.12 | Medium |
| Splitting theme JavaScript | INP | EUR 1,000 to 3,000 | INP minus 50 to 150 ms | Medium |
The first three rows often solve 60 to 70% of the problem for under EUR 2,500. Live chat widgets and ad tracking tools are the usual INP culprits.
Mini case study
Philip, managing director of a 28-person London SME that maintains aerospace production lines, had a 60-page WordPress site in amber on mobile: LCP 4.1 s, INP 380 ms, CLS 0.22. Audit at EUR 1,400 excl. VAT, level 2 fixes at EUR 5,200, completed in 4 weeks. Total: EUR 6,600 excl. VAT.
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After the fixes: LCP 1.9 s, INP 160 ms, CLS 0.04, all URLs green in Search Console within 28 days. Within 4 months, organic sessions on service pages rose from 1,050 to 1,300 per month (plus 24%) and quote requests from 14 to 19 per month. With an average deal of EUR 12,000 and a 25% close rate, the 5 extra requests represent about EUR 15,000 of additional monthly revenue, so the spend is recovered in under a month of signed work.
FAQ
How much does a Core Web Vitals audit cost in 2026?
EUR 900 to 2,500 excl. VAT depending on site size and technology. The audit should deliver a prioritised list of fixes with an estimated cost and gain for each.
Can we fix it ourselves with a caching plugin?
Partly: a caching and image compression plugin can cut LCP by 0.5 to 1 s. It almost never solves INP or CLS, which depend on the theme and third-party scripts.
How long until Google reflects the fixes?
Field data covers a rolling 28 days. Expect 4 to 6 weeks for URLs to turn green in Search Console, then 2 to 4 months for the traffic effect.
Is the traffic gain guaranteed?
No. Core Web Vitals are one ranking factor among many. On B2B sites that already rank reasonably, we see 15 to 30% more organic sessions on fixed pages, as a 2026 order of magnitude.
Is it better to fix or rebuild the site?
If fixes exceed EUR 9,000 or the theme is over 6 years old, migrating to a lighter architecture is often more cost-effective over 3 years.
Let's scope your project. Send us your site URL and a Search Console export: we price the audit and fixes between EUR 900 and 9,000 excl. VAT, delivered in 2 to 5 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.
