The verdict in three sentences
An ageing WordPress stacks slowness, plugin vulnerabilities and rising maintenance costs: migrating to a headless CMS with a Next.js front end is now a risk calculation, not a luxury. For a London SME, budget GBP 12,000 to 30,000 depending on content volume, with LCP dropping from 4.5 s to 1.2 s and the attack surface cut by roughly two-thirds. SEO is fully preserved provided the redirect plan is scoped from day one.
Migration cost by content volume
Price depends mostly on page count, template complexity and how many plugins must be replaced by custom code. 2026 order-of-magnitude estimate for the London market:
| Site profile | Pages / posts | Plugins to migrate | Cost | Timeline |
|---|---|---|---|---|
| Simple brochure | < 30 | 3-5 | GBP 12,000 - 16,000 | 8 weeks |
| Site + active blog | 30-120 | 6-10 | GBP 16,000 - 22,000 | 10 weeks |
| Site + catalogue | 120-400 | 10-15 | GBP 22,000 - 30,000 | 12-14 weeks |
| Multi-site / intranet | 400+ | 15+ | custom (30,000+) | 14+ weeks |
The most underestimated line item is content reuse: clean import of posts, media and SEO metadata into the headless CMS (Sanity or Strapi).
3-year TCO and hosting savings
A decoupled architecture (Next.js front end, headless CMS, edge hosting) reshapes the total cost of ownership.
| Indicator | WordPress before | Headless after | Gain |
|---|---|---|---|
| LCP (product page) | 4.5 s | 1.2 s | -73 % |
| Mobile Lighthouse score | 42 | 96 | +54 pts |
| Critical vulns/year | 8-12 | 1-2 | -80 % |
| Hosting cost/month | GBP 80 | GBP 30 | -63 % |
| Security patching time | 6 h/month | 1 h/month | -83 % |
| Organic traffic (6 months) | base 100 | 118-135 | +18 to +35 % |
Over 3 years, hosting and maintenance savings alone typically recover GBP 6,000 to 9,000, before counting avoided incident costs.
Mini case study
Sarah, IT lead at a 45-person industrial SME in London, runs a 180-page WordPress with 12 plugins. She faces 2 security incidents a year (average GBP 4,000 remediation each) and a 61 % mobile bounce rate. Chosen migration: GBP 21,000 over 11 weeks. 12-month result: hosting from GBP 80 to 30/month (GBP 600/year saved), zero incidents (GBP 8,000 avoided), +26 % organic traffic and +14 % quote requests. Payback in 14 months, before counting the sales-image gain.
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FAQ
Will I lose my rankings during migration?
No, if the 301 redirect plan covers 100 % of indexed URLs and title/meta tags carry over. Done right, a migration recovers traffic in 4 to 8 weeks and often exceeds the previous level by 15 to 30 %.
Can I keep WordPress just as a back office?
Yes, that is WordPress headless: keep WP admin as the CMS and serve the front end in Next.js. It is 15 to 25 % cheaper than a full switch to Sanity, but less performant long term.
How long will my editors need training?
Budget 1 to 2 half-days. A modern headless CMS (Sanity, Strapi) offers a cleaner editing interface than a plugin-heavy WordPress admin.
What happens to my forms and local SEO?
Forms are rebuilt cleanly (anti-spam, GDPR-compliant) and local SEO is strengthened with LocalBusiness schema and structured data, often missing from WordPress installs.
Does maintenance cost really drop?
Yes: no more weekly plugin updates or breakage risk. You typically go from 6 h to 1 h of security maintenance per month.
Let's scope your project. Send us your page count, critical plugins and deadline: we will price the WordPress-to-headless migration and the redirect 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.
