The verdict in three sentences
A controlled website migration costs in 2026 between EUR 3,000 and 9,000 and takes 4 to 7 weeks, 301 redirect plan and QA included. Without a method, a 30 to 60 % organic traffic drop over 3 months is common and sometimes irreversible. With an exhaustive URL mapping, the loss stays under 5 % and is recovered in 6 to 10 weeks.
Why a migration crashes SEO
Changing CMS, URL structure or domain breaks the link between accumulated authority and the new pages. Google temporarily loses track of your content if redirects are not perfect. Here are the most common causes of loss and their impact.
| Cause of loss | Traffic impact | Prevention |
|---|---|---|
| URLs changed without 301 redirect | -20 to -40 % | Exhaustive mapping |
| Deleted or thinned content | -10 to -25 % | Content audit |
| Lost meta tags | -5 to -15 % | Export/reimport |
| Performance drop (LCP) | -5 to -10 % | Technical QA |
| Untreated 404 errors | -10 to -30 % | Post-migration crawl |
The sum of these risks explains why a botched migration can cost months of traffic. Conversely, a rigorous method neutralises each cause.
The cost of a controlled migration
The budget depends on URL volume, target CMS complexity and QA depth. Here is the 2026 grid.
| Site size | Number of URLs | Cost | Timeline |
|---|---|---|---|
| Small marketing site | < 50 | EUR 3,000 - 4,500 | 4 - 5 wks |
| Mid-sized site | 50 - 300 | EUR 4,500 - 6,500 | 5 - 6 wks |
| Large site / e-commerce | 300 - 2,000 | EUR 6,500 - 9,000 | 6 - 7 wks |
This budget covers the initial audit, URL-by-URL mapping, 301 redirect setup, pre-launch QA and crawl monitoring for 4 weeks after go-live.
The checklist that protects your rankings
A safe migration rests on a non-negotiable sequence: full crawl of the old site, mapping of each URL to its target, 301 redirects (never 302), preservation of title/meta tags, hreflang verification, updated sitemap submitted to Google, and daily monitoring of 404s and rankings for 6 weeks.
Mini case study
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Karim, digital manager of an industrial SME in Rotterdam, migrates his 180-page site from WordPress to a Next.js stack. His current traffic is 25,000 visits/month. Without a plan, a 40 % drop (10,000 visits lost) would have cost, at a value of EUR 0.80 per visit, around EUR 8,000 in monthly value. He invests EUR 5,800 in a controlled migration with exhaustive mapping: the loss is limited to 4 % (1,000 visits) and recovered in 8 weeks. The avoided gap exceeds EUR 7,000 in monthly traffic, paying for the service in the first month.
FAQ
How much does a migration without SEO loss cost?
Between EUR 3,000 and 9,000 in 2026 depending on the number of URLs. A 180-page site typically migrates for EUR 5,000 to 6,500, redirect plan and QA included.
How much traffic can I lose during a migration?
Without a method, 30 to 60 % over 3 months, sometimes permanently. With an exhaustive 301 mapping and technical QA, the loss stays under 5 % and recovers in 6 to 10 weeks.
Do I have to redirect every old URL?
Yes, each indexed URL must point via 301 to its closest target. Temporary 302s and redirect chains must be avoided as they dilute authority.
How long to recover rankings?
From 6 to 10 weeks after go-live for a well-run migration. Daily monitoring of 404s and rankings lets you fix any oversights quickly.
Can I migrate and redesign at the same time?
Yes, it is common, but it increases risk: isolate the redirect plan and test performance before launch. Allow 1 to 2 extra weeks.
Let's scope your project. Send us your current CMS, URL count and target CMS: we define a secure migration plan and an indicative budget between EUR 3,000 and 9,000. 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.
