The verdict in three sentences
A 4.8 s mobile LCP on a 400-product catalogue costs you quote requests every week, because Google ranks slow pages lower and buyers leave before seeing the price or the datasheet. The fix almost always comes down to three workstreams: images (AVIF, sizing, preloading), server rendering of product pages and caching through a CDN. Realistic total budget in 2026: EUR 5,500 to 15,000 excl. VAT, with measurable returns in 3 to 6 months.
Where the 4.8 seconds come from: a typical industrial catalogue diagnosis
On B2B industrial websites, the LCP (Largest Contentful Paint) is usually the main product photo or a product-range banner. The causes repeat from site to site, and a serious audit prices each one before touching the code.
| Common cause | Typical mobile LCP impact | Fix | Indicative 2026 cost |
|---|---|---|---|
| 1.5 to 3 MB JPEG product photos | +1.5 to 2.5 s | AVIF/WebP conversion, responsive sizes | EUR 800 to 2,500 |
| Main image lazy-loaded | +0.5 to 1 s | Preload and high priority on the LCP image | EUR 300 to 800 |
| WordPress or PrestaShop theme loaded with plugins | +0.8 to 1.5 s | Clean-up, removal of unused scripts | EUR 1,500 to 4,000 |
| Shared hosting, TTFB > 800 ms | +0.6 to 1.2 s | Server cache, dedicated hosting or CDN | EUR 20 to 80/month + EUR 500 |
| Blocking fonts and third-party scripts (chat, tracking) | +0.3 to 0.8 s | Deferred loading, self-hosted fonts | EUR 400 to 1,200 |
| Product pages rendered in the browser (heavy JavaScript) | +1 to 2 s | Server rendering or static generation | EUR 3,000 to 8,000 |
The initial audit, billed at EUR 1,500 to 3,000, should deliver a prioritised report: field data (Google CrUX), lab data (Lighthouse on 20 to 30 representative product pages) and the expected gain per fix. Without that estimate, you risk spending EUR 8,000 on a workstream that only saves 0.3 s.
What fixes cost depending on your CMS
Cost mostly depends on the site's technology. A 400-product catalogue on a recent CMS is quick to fix; an ageing in-house site sometimes needs a partial rebuild of product page templates.
| Platform | Fixes only | Timeline | Target mobile LCP | Note |
|---|---|---|---|---|
| WordPress + WooCommerce | EUR 4,000 to 7,000 | 3 to 5 weeks | 2.0 to 2.4 s | Depends on theme and plugins |
| PrestaShop 8 | EUR 5,000 to 9,000 | 4 to 6 weeks | 2.1 to 2.5 s | Modules often need replacing |
| Shopify (B2B storefront) | EUR 3,000 to 6,000 | 2 to 4 weeks | 1.8 to 2.3 s | Hosting already optimised |
| In-house CMS (legacy PHP) | EUR 8,000 to 12,000 | 6 to 10 weeks | 2.0 to 2.5 s | Often a template rebuild |
| Next.js / headless | EUR 2,500 to 5,000 | 2 to 3 weeks | 1.2 to 1.8 s | Best technical ceiling |
| Full catalogue rebuild | EUR 18,000 to 35,000 | 3 to 4 months | 1.2 to 1.8 s | When technical debt is too heavy |
Recurring costs come on top: CDN and on-the-fly image optimisation at EUR 20 to 80 per month for 400 product pages and a few thousand monthly visits, plus Core Web Vitals monitoring (often included in a maintenance plan).
What to demand in the quote
A performance quote should commit to measurable results, not just hours. Ask for:
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
- a numeric target: mobile LCP < 2.5 s at the 75th percentile on product pages, INP < 200 ms, CLS < 0.1;
- before/after measurement on the same page sample;
- the list of removed plugins or scripts, signed off by your marketing team;
- a 28-day control period, the time Google's field data needs to refresh.
Mini case study
Sanne, marketing manager at a lifting equipment manufacturer in Amsterdam, runs a 400-page PrestaShop catalogue. The site gets 6,000 organic visits a month and 40 quote requests, with a 20% close rate and an average order of EUR 9,000, roughly EUR 72,000 of monthly revenue from the website.
After the audit (EUR 2,400), fixes (EUR 7,500) and CDN (EUR 45/month), mobile LCP drops from 4.8 s to 2.2 s. Conservative assumption: +20% requests within 6 months, i.e. 8 more quotes a month, 1.6 orders and about EUR 14,400 of extra monthly revenue. At a 30% gross margin, that is EUR 4,320 of extra margin per month: the EUR 9,900 investment pays back in just over two and a half months once the gain is in place.
FAQ
How long before Google reflects the change? Core Web Vitals field data is computed over a rolling 28 days, so allow 4 to 6 weeks for the status to turn green in Search Console. The effect on organic traffic is usually measured between 3 and 6 months.
Is AVIF supported by every browser? In 2026, over 95% of mobile browsers read AVIF. An image CDN automatically serves WebP or JPEG to the remaining browsers, with no manual work.
Do we need to rebuild the whole site to get under 2.5 s? Not in 8 cases out of 10: targeted fixes (images, cache, scripts) are enough for EUR 4,000 to 12,000. A rebuild, from EUR 18,000, is only justified if the CMS is obsolete or unmaintainable.
Is the 15 to 30% uplift in quotes guaranteed? No, it is a 2026 order of magnitude observed on comparable B2B catalogues. It also depends on product page quality, keyword positioning and local competition.
Who should monitor the metrics after delivery? Monthly Core Web Vitals monitoring, included in maintenance from about EUR 115 per month, prevents a new plugin or a 4 MB photo from pushing LCP back up.
Let's scope your project. Send us your catalogue URL: we will price the audit, the priority fixes and the timeline, with a committed LCP target. 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.
