The verdict in three sentences
For a B2B SMB in Amsterdam whose site shows a 450 ms INP and a 4.2 s LCP on mobile, a Core Web Vitals audit costs EUR 1,500 to 3,500 excl. VAT in 2026, and fixes EUR 3,000 to 12,000 depending on the CMS. The realistic target, LCP under 2.5 s and INP under 200 ms, is reached in 4 to 6 weeks. Measured gains in quote requests range from +8 to +20%, while a simple EUR 60 a year caching plugin rarely fixes INP.
What the audit covers and what fixes cost
A serious audit is more than a PageSpeed score. It combines field data (CrUX report, Search Console) with lab measurements, identifies the responsible third-party scripts and ranks fixes by expected gain. Here are 2026 orders of magnitude for a B2B site of 30 to 200 pages.
| Service | WordPress | Webflow or Wix | Next.js or custom |
|---|---|---|---|
| Full audit (field and lab) | EUR 1,500 to 2,500 | EUR 1,500 to 2,000 | EUR 2,000 to 3,500 |
| Image optimization (AVIF, sizing, lazy loading) | EUR 800 to 2,000 | EUR 500 to 1,200 | EUR 600 to 1,500 |
| Reducing and deferring third-party scripts | EUR 1,000 to 3,000 | EUR 800 to 2,000 | EUR 1,000 to 2,500 |
| INP fixes (JavaScript, event handling) | EUR 1,500 to 4,000 | Limited by platform | EUR 1,500 to 3,500 |
| Fonts, critical CSS, layout stability (CLS) | EUR 500 to 1,500 | EUR 400 to 1,000 | EUR 400 to 1,200 |
| Hosting, CDN, server cache | EUR 300 to 1,500 | Included | EUR 300 to 800 |
| Total fixes | EUR 4,100 to 12,000 | EUR 3,000 to 6,000 | EUR 3,800 to 9,500 |
On Webflow or Wix the cost is lower but so is the performance ceiling: some platform scripts cannot be changed, and INP rarely drops below 250 ms on rich pages.
EUR 60 caching plugin or targeted fixes
The common reflex is to install a premium caching plugin. It improves server response time, but INP depends mostly on JavaScript running in the browser. Comparison on a typical B2B WordPress site, indicative median values.
| Mobile indicator | Starting point | Caching plugin only (EUR 60 a year) | Audit and fixes (EUR 8,000) |
|---|---|---|---|
| LCP | 4.2 s | 3.3 s | 2.1 s |
| INP | 450 ms | 430 ms | 170 ms |
| CLS | 0.18 | 0.17 | 0.04 |
| Pages rated good in Search Console | 12% | 25% | 85% |
| Quote form conversion rate | 1.6% | 1.7% | 1.9 to 2.1% |
| Implementation time | 1 day | 1 day | 4 to 6 weeks |
The plugin is a good first step, not a solution. The pages that matter for a B2B site (offers, case studies, quote form) are often the ones loading the most scripts: chat, analytics, maps, video, CRM.
Calculating the return on investment
The formula is simple: extra quote requests x close rate x average margin. With 3,000 monthly visits and conversion rising from 1.6% to 1.9%, you get 9 more requests a month. At a 20% close rate and EUR 4,000 gross margin per contract, the gain is about EUR 7,200 a month. Even dividing that by three to stay cautious, a EUR 10,000 budget pays back in under 5 months.
Mini case study
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Sanne, marketing manager of an Amsterdam SMB selling industrial storage systems, sees a 450 ms INP and a 4.2 s LCP in Search Console. The WordPress site gets 2,500 visits a month and generates 38 quote requests. She orders a EUR 2,200 audit and EUR 7,400 of fixes: 6 third-party scripts removed, chat loaded on interaction, AVIF images, system font. After 6 weeks: LCP at 2.0 s, INP at 160 ms. Requests rise to 44 a month, +16%. With a 25% close rate and EUR 3,000 margin per contract, the monthly gain is 6 x 0.25 x 3,000 = EUR 4,500. Total investment of EUR 9,600 repaid in just over 2 months.
FAQ
How much does a Core Web Vitals audit cost for a B2B site in 2026?
EUR 1,500 to 3,500 depending on site size and CMS. The audit should include CrUX field data and a prioritized fix list with estimated gains.
What budget should we plan for fixes?
EUR 3,000 to 12,000 depending on the CMS and number of third-party scripts. A plugin-heavy WordPress site often lands between EUR 6,000 and 9,000.
How quickly do scores improve?
Lab measurements change immediately, but Google field data updates over a rolling 28 days. Allow 4 to 6 weeks to see good status in Search Console.
Is a caching plugin enough?
It often improves LCP by 15 to 25% but does little for INP. If your INP exceeds 300 ms, the problem is JavaScript and needs targeted fixes.
What impact on quote requests?
On comparable B2B sites we see +8 to +20% more requests once all three indicators turn green. The effect is stronger on mobile, often 45 to 60% of traffic.
Let's scope your project. Send us your site URL: we analyze your Core Web Vitals data and price the audit, priority fixes and timeline. 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.
