The verdict in three sentences
A B2B site whose mobile LCP exceeds 4 s loses rankings and demo requests, and a caching plugin rarely fixes it. In 2026 in Amsterdam, budget EUR 1,500 to 4,000 excl. VAT for the audit and EUR 3,000 to 12,000 for the fixes, depending on the stack and number of templates. The expected return, as a 2026 order of magnitude, is an 8 to 15% conversion lift on organic pages after 3 to 6 weeks of work.
What a serious Core Web Vitals audit includes
A useful audit goes beyond a PageSpeed score. It combines field data (CrUX report, Search Console) with lab measurements (Lighthouse, WebPageTest) on each template: home, product page, feature page, blog post, demo form. It pinpoints the exact cause of each failure: a hero image without priority, a render-blocking web font, a chat or tag manager script hogging the main thread, layout shifts caused by cookie banners.
| Audit level | Scope | Deliverables | 2026 price (EUR excl. VAT) |
|---|---|---|---|
| Express | 3 templates, Lighthouse data | 10-page report, 10 prioritised actions | 1,500 to 2,000 |
| Standard | 6 to 8 templates, CrUX + Lighthouse | Detailed report, costed backlog, 2 h workshop | 2,200 to 3,000 |
| In-depth | Full site, third-party scripts, RUM | Backlog, fix prototypes, 30-day follow-up | 3,000 to 4,000 |
| Light fixes | Images, fonts, preloading | Production release, before/after measurement | 3,000 to 5,000 |
| Heavy fixes | Rendering rework, third-party scripts, critical CSS | 3 to 6 week sprint | 6,000 to 12,000 |
| Monthly monitoring | CrUX alerts, regressions | Monthly report | 300 to 600 per month |
Thresholds to target and their business impact
Google assesses three metrics at the 75th percentile of real visits. A site passes when all three are green on mobile. For a B2B vendor, the gain is not only about rankings: a page that renders in 2 s instead of 4.8 s keeps more visitors on their way to the form.
| Metric | "Good" threshold | Typical pre-audit value | Post-fix target |
|---|---|---|---|
| LCP (main content render) | < 2.5 s | 4.8 s on mobile | 2.0 to 2.3 s |
| INP (responsiveness) | < 200 ms | 350 to 450 ms | 120 to 180 ms |
| CLS (visual stability) | < 0.1 | 0.18 to 0.25 | 0.02 to 0.06 |
| Mobile page weight | No official threshold | 3.5 to 5 MB | 1.2 to 1.8 MB |
| Third-party scripts | No official threshold | 12 to 20 tags | 6 to 9 tags |
| Form conversion rate | Varies | 1.6% | 1.75 to 1.85% (+8 to 15%) |
The 3 to 6 week timeline includes the release plus 28 days of CrUX collection, which Search Console needs before it reflects the improvement.
How to choose a provider in Amsterdam
Ask for three things before signing: a sample costed backlog from a previous audit, a commitment on field values (CrUX) rather than Lighthouse alone, and a clear split between the audit price and the fix price. Be wary of "guaranteed score of 100" packages: a perfect lab score does not guarantee good field data if your visitors browse on 4G on the train to Rotterdam.
Mini case study
Thomas, marketing lead at a B2B SaaS vendor in Amsterdam, gets 9,000 organic visits a month and converts 1.6% into demo requests, or 144 leads. His mobile LCP is 4.8 s. He orders a standard audit (EUR 2,600) and fixes (EUR 7,400), EUR 10,000 excl. VAT in total. After 6 weeks, LCP drops to 2.2 s and conversion rises to 1.8% (+12.5%), or 162 leads a month. With 18 extra leads, a 10% close rate and an average annual contract of EUR 6,000, the gain is about EUR 10,800 of annual revenue per month of traffic. The investment pays back within one month of new deals.
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FAQ
How much does a Core Web Vitals audit cost in 2026?
Between EUR 1,500 and 4,000 excl. VAT depending on the number of templates and depth. A standard audit on 6 to 8 templates lands around EUR 2,200 to 3,000.
How long before the effect shows in Search Console?
Allow 28 days of field data after release. With 2 to 4 weeks of work, the total timeline is 3 to 6 weeks.
Do we need to rebuild the site to pass Core Web Vitals?
Rarely. In 7 cases out of 10, fixes at EUR 3,000 to 5,000 (images, fonts, third-party scripts) are enough to get LCP under 2.5 s.
Is INP harder to fix than LCP?
Often yes, because it depends on JavaScript: chat, tag manager, A/B testing tools. Cutting third-party tags from 15 to 8 frequently brings INP from 400 ms to under 200 ms.
What conversion lift should we expect?
The 2026 order of magnitude is 8 to 15% on organic pages, provided the form and offer stay unchanged during measurement.
Let's scope your project. We price the audit of your key templates and the fix budget, EUR 1,500 to 12,000 excl. VAT depending on your stack, with a 3 to 6 week schedule. 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.
