The verdict in three sentences
In 2026, a Core Web Vitals audit for a B2B e-commerce site in Berlin costs 1,200 to 3,500 EUR, and the follow-up optimizations run 3,000 to 9,000 EUR depending on technical debt. The targets are LCP < 2.5s, INP < 200ms and CLS < 0.1, with an expected conversion lift of +8 to +20%. The average timeline is 3 to 6 weeks: it is one of the best effort-to-impact SEO levers.
What a performance audit covers in 2026
A serious audit measures the three Core Web Vitals on real-user data (CrUX) and in the lab, then ranks fixes. Here are the line items and their ranges.
| Audit item | 2026 range (EUR) | Deliverable |
|---|---|---|
| Full performance audit | 1,200 - 3,500 | Report + prioritized backlog |
| Image / lazy-load optimization | 800 - 2,000 | WebP/AVIF, CDN |
| Critical render path rework (CSS/JS) | 1,500 - 4,000 | LCP < 2.5s |
| Blocking JS reduction (INP) | 1,200 - 3,500 | INP < 200ms |
| Layout stabilization (CLS) | 600 - 1,800 | CLS < 0.1 |
| Caching / edge | 900 - 2,500 | TTFB < 600ms |
On a heavy B2B catalog (filters, customer accounts, custom pricing), the blocking JS item is often the costliest because it touches the application core.
One-off optimization vs technical redesign
Should you fix the existing site or rebuild on a clean base? A numeric comparison.
| Criterion | One-off optimization | Technical redesign |
|---|---|---|
| 2026 budget | 3,000 - 9,000 EUR | 25,000 - 60,000 EUR |
| Timeline | 3 - 6 weeks | 3 - 6 months |
| Conversion lift | +8 - 20% | +15 - 35% |
| Project risk | Low | Medium to high |
| Lifespan of the gain | 1 - 2 years | 4 - 6 years |
| Business interruption | None | Migration to plan |
When the technical foundation is recent, one-off optimization delivers the best immediate return; a redesign is only justified if the stack is obsolete or the debt blocks all evolution.
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Mini case study
Laure, e-commerce director of a B2B distributor in Berlin, generates 2.4M EUR in online revenue at a 1.8% conversion rate. Her mobile LCP sits at 4.1s and her INP at 310ms. She invests 2,500 EUR in the audit then 7,000 EUR in optimizations, totaling 9,500 EUR. After five weeks, LCP drops to 2.2s, INP to 170ms, and conversion rises to 2.1%, a +16.7% gain. On 2.4M EUR of revenue, that lift represents roughly +400,000 EUR in annual sales: the investment pays back in under two weeks of surplus.
FAQ
How much does a Core Web Vitals audit cost in 2026? Between 1,200 and 3,500 EUR for the audit alone; with optimizations, budget an overall 4,200 to 12,500 EUR depending on technical debt.
What thresholds must be met? The 2026 Google targets remain LCP < 2.5s, INP < 200ms and CLS < 0.1, measured at the 75th percentile of real users.
What conversion lift can I expect? Crossing the thresholds usually brings +8 to +20% conversion, more on mobile where speed impact is strongest.
How long do fixes take? Expect 3 to 6 weeks for a one-off optimization, versus 3 to 6 months if a technical redesign is required.
Does performance really improve SEO? Yes: Core Web Vitals are a ranking signal, but above all a direct driver of conversion and lower bounce rate.
Let's scope your project. Send us your stack, your traffic volume and your current scores, and we'll price the audit and optimization plan. 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.
