The verdict in three sentences
Migrating a saturated WordPress to headless (Next.js + CMS) realistically costs EUR 15,000 to 22,000 and spans 8 to 11 weeks. The gain is not cosmetic: LCP cut by three or four, +15 to 30 % conversion and comfortable editing for your teams. The line item never to neglect is 301 redirects: it protects your SEO during the switch.
The budget line by line
an honest headless quote details every item. Here is the 2026 order-of-magnitude breakdown for a 20-to-40-page B2B site.
| Item | Range | What it covers |
|---|---|---|
| Audit + architecture | EUR 2,500 | Mapping, stack choice, content model |
| Content migration | EUR 3,000-6,000 | Pages, media, CMS structuring |
| Front-end development | EUR 8,000-14,000 | Next.js, components, design integration |
| 301 redirects + SEO | EUR 2,000 | URL mapping, tags, sitemap, hreflang |
| QA + go-live | EUR 1,500 | Testing, QA, DNS switch |
| Project total | EUR 15,000-22,000 | Delivered and in production |
Add hosting: EUR 60 to 200/month on Vercel or Scaleway depending on traffic and CDN needs. Far cheaper than maintaining a beefy WordPress server.
The measurable gains after migration
Headless is only justified by performance and conversion. Here are the typical before/after gaps seen on B2B projects.
| Metric | WordPress before | Headless after | Change |
|---|---|---|---|
| Mobile LCP | 4.2 s | 1.1 s | -74 % |
| Lighthouse perf score | 42/100 | 96/100 | +128 % |
| Conversion rate | 1.2 % | 1.6 % | +33 % |
| Hosting cost/month | EUR 180 | EUR 90 | -50 % |
| Content update time | Slow, unstable | Instant | — |
| Security attack surface | High (plugins) | Reduced | — |
Going from 42 to 96 on Lighthouse performance is not vanity: Google favours these sites and your mobile prospects stop bouncing before the page loads.
Mini case study
Nadia, CEO of a 30-person B2B services SME in Bordeaux, is stuck with a WordPress at 4.2 s LCP capping at 1.2 % conversion. She invests EUR 18,500 in a headless migration over 9 weeks. After three months, LCP drops to 1.1 s and conversion climbs to 1.6 %. On 6,000 monthly visitors, that means 96 leads instead of 72, i.e. 24 extra qualified leads. At an 18 % close rate and an average value of EUR 5,500, that is EUR 23,700 in additional monthly revenue. The project pays back in under a month of stabilised traffic.
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FAQ
Why migrate if WordPress still works?
Because a 4 s LCP costs conversions daily and ageing plugins create security debt. Headless cuts load time by 3 to 4 and reduces the attack surface.
Can we keep the WordPress editing interface?
Yes, by keeping WordPress as a headless CMS (REST/GraphQL API) with Next.js on the front. Your writers keep their tool; only the rendering becomes ultra-fast.
How long does the migration really take?
Allow 8 to 11 weeks for 20 to 40 pages. The main delay factor remains content to migrate or rewrite: plan that work early.
What happens to my Google rankings?
With an exhaustive 301 redirect map and preserved performing URLs, the loss is limited to a few points over 4 to 6 weeks, then rankings recover thanks to speed.
Is hosting really cheaper?
Often yes: EUR 60 to 200/month on Vercel/Scaleway versus a beefy WordPress VPS to maintain. And scaling is automatic during traffic spikes.
Let's scope your project. Give us your WordPress URL, page volume and monthly traffic: we price the headless migration (order of magnitude EUR 15-22k) and the exact 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.
