The verdict in three sentences
Moving off a monolithic WordPress to a headless architecture (Next.js + CMS API) costs 8,000-25,000 € in 2026 depending on content volume and front-end complexity. The payback shows on three lines: performance (LCP -40 to -60 %, TTFB divided by 2 to 3), security (smaller attack surface, maintenance -35 %) and scalability. For a CIO the real question isn't *how much it costs* but *how much it costs to stay* on a stack that throttles SEO and multiplies patches.
The line items of a headless migration
A migration is more than building the front end. It breaks down into distinct line items, each priced separately, which lets you phase the investment or prioritize.
| Line item | Scope | 2026 range |
|---|---|---|
| Audit & architecture | Content mapping, CMS choice, data schema | 1,500 - 4,000 € |
| Content export / reimport | Articles, media, taxonomies migration | 1,500 - 4,000 € |
| Front rebuild (Next.js) | Components, pages, design system | 5,000 - 14,000 € |
| Headless CMS integration | API, preview, editorial workflow | 2,000 - 5,000 € |
| SEO & redirects | 301 plan, meta, sitemap, hreflang | 1,200 - 3,000 € |
| QA & go-live | Testing, CI/CD, DNS switch | 800 - 2,500 € |
For an 80-to-200-page site, the real total usually lands between 11,000 and 18,000 € (2026 order of magnitude), with the front end alone weighing nearly half the budget.
Before / after: what performance changes
The gain is not cosmetic. A headless stack removes on-the-fly PHP rendering and plugin weight, which translates into measurable metrics.
| Metric | Typical WordPress | After headless | Gain |
|---|---|---|---|
| LCP (mobile) | 4.2 s | 1.8 s | -57 % |
| TTFB | 850 ms | 280 ms | -67 % |
| Page weight (median) | 3.1 MB | 1.2 MB | -61 % |
| Critical plugins to patch | 22 | 4 | -82 % |
| Security maintenance / year | 3,800 € | 2,500 € | -35 % |
| Lighthouse perf score | 48 | 94 | +96 % |
Each second of LCP recovered weighs directly on conversion and ranking: Google treats Core Web Vitals as a ranking signal, and a site with TTFB halved sees its bounce rate drop noticeably.
Mini case study
Marc, CIO of a B2B software vendor in Lyon, runs a 140-page WordPress with 24 plugins. His annual maintenance hits 3,800 € for security patches alone, and two 2025 incidents took the site down for 11 cumulative hours. Headless migration quote: 15,500 € (audit 3,000, reimport 2,500, front 8,000, SEO 2,000). Over 3 years, saved security maintenance (1,300 €/yr) plus avoided incidents (estimated at 4,000 € of lost leads in 2025) bring the real net cost near 7,600 €, meaning ROI is reached by the end of year two.
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
FAQ
How long does a WordPress-to-headless migration take?
Budget 8 to 14 weeks depending on volume. Content reimport and the redirect plan are the two items that push the schedule past 100 pages.
Will we lose SEO traffic during migration?
No, if the 301 redirect plan is clean and tested: loss is generally under 5 % over 4 to 6 weeks, then traffic recovers thanks to the performance gain.
Can we keep the WordPress editing interface?
Yes, WordPress can stay in headless mode as an admin CMS (via its REST/GraphQL API), or you switch to a dedicated API CMS. The choice depends on editor comfort and integration budget (2,000 to 5,000 €).
Is headless worth it for a small brochure site?
Below 30 pages with no heavy traffic stakes, the cost gap (8,000 € minimum) rarely pays off. Headless becomes relevant past 60-80 pages or when performance drives revenue.
Do we have to redo everything at once?
No: you can migrate in batches (blog first, then product pages), which smooths the budget and lowers risk. The final DNS switch happens once QA is signed off.
Let's scope your project. Share your page volume, current CMS and indicative budget, and we'll price each migration line item separately. 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.
