The verdict in three sentences
A migration without SEO loss costs between 4,000 and 15,000 EUR excl. tax in 2026, with most of the budget going into the 301 redirect plan and post-launch verification. The real risk is not the price of the work but a sloppy migration: a 30-70% organic traffic drop and a 3-to-6-month recovery. Paying for a serious migration audit is always cheaper than buying that traffic back through ads.
What the migration budget covers
Price depends mainly on the number of URLs to process and the level of existing traffic to protect. A 40-page brochure site does not carry the same stakes as a 5,000-URL site with six-figure SEO history.
| URL volume | Monthly traffic | 2026 SEO migration budget (EUR excl. tax) | Risk window |
|---|---|---|---|
| < 50 URLs | < 5,000 visits | 4,000 – 6,000 | 2 – 3 weeks |
| 50 – 300 URLs | 5,000 – 30,000 | 6,000 – 9,000 | 3 – 4 weeks |
| 300 – 1,500 URLs | 30,000 – 100,000 | 9,000 – 12,000 | 4 – 6 weeks |
| 1,500 – 5,000 URLs | 100,000 – 300,000 | 12,000 – 15,000 | 6 – 8 weeks |
| > 5,000 URLs | > 300,000 | on quote (15,000+) | 8 weeks+ |
This budget includes redirect mapping, metadata retention, before/after comparative crawls and 8-week rank tracking. It excludes the visual redesign itself, which is a separate line item.
The redirect plan, the critical item
Every indexed old URL must point to its closest equivalent through a permanent 301 redirect. A redirect chain or a jump to a 404 wastes the accumulated SEO value.
| Technical item | Detail | Effort (days) | 2026 cost (EUR excl. tax) |
|---|---|---|---|
| URL extraction & mapping | Full crawl + correspondence table | 1 – 3 | 800 – 2,400 |
| Writing the 301s | Server rules or redirect file | 1 – 2 | 600 – 1,600 |
| Metadata retention | Title, meta, canonicals, hreflang | 1 – 2 | 700 – 1,500 |
| Before/after crawl | Screaming Frog / log comparison | 1 | 500 – 900 |
| 8-week rank tracking | Weekly reporting + fixes | 2 – 4 | 1,400 – 3,200 |
The rule: no 301 should produce a second redirect. A two-hop chain dilutes the signal and slows crawling.
The cost of a botched migration
A site doing 60,000 organic visits per month, valued at 1.50 EUR per equivalent ad click, generates 90,000 EUR of monthly media value. A 40% drop erases 36,000 EUR of value each month during recovery. That is why saving 5,000 EUR on the migration audit is the worst possible calculation.
Mini case study
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Thomas, e-commerce director at a B2B industrial-supplies distributor in Lille, migrates 2,200 URLs from Magento to a new platform. Current traffic: 85,000 organic visits per month. SEO migration budget: 12,500 EUR excl. tax. Without a redirect plan, an estimated 45% drop would cost him, at 1.40 EUR per click, roughly 53,000 EUR of lost media value over the first three months. By investing 12,500 EUR he limits the transient loss to 8% over three weeks, an immediate ROI above 3 to 1 on protected traffic alone.
FAQ
How long is the risk window after a migration?
Expect 2 to 8 weeks depending on URL volume. Google must recrawl and reassign the value of old pages; on a large site, full stabilization takes up to two months.
Can you migrate with zero traffic loss?
A transient loss of 5 to 15% is normal in the first weeks, even on a perfect migration. The goal is to return to the initial level within 4 to 6 weeks, not to avoid any dip.
Should you keep the same URLs?
Yes, whenever possible. Keeping existing URLs removes the need for redirects and cuts risk to almost zero. Only change the structure if it is genuinely penalizing you.
Do the blog and images count in the volume?
Yes. Every indexed URL counts, including articles, categories and images that draw Google Images traffic. Underestimating this volume is the leading cause of botched migrations.
When in the year should you launch the migration?
Avoid commercial peaks. An e-commerce site ideally migrates in January or summer, never in November before the holidays. A transient dip during your high season costs the most.
Let's scope your project. Give us your URL volume, current organic traffic and target platform, and we'll price the redirect plan and risk window. 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.
