The verdict in three sentences
A 301 redirect tells Google: this page has permanently moved here, and transfers most of its SEO value. The lethal trap is not forgetting a redirect, it is redirect chains (A to B to C) that dilute link equity and slow the crawl. A clean plan for 400 to 1,200 URLs costs 1,400 to 3,200 EUR and wraps up in 2 weeks.
Map before you redirect
Mapping is the foundation: without an exhaustive URL inventory, zero loss cannot be guaranteed.
| URL volume | 2026 range (EUR) | Timeline | Mapping effort |
|---|---|---|---|
| < 200 | 900 - 1,400 | 1 week | Low |
| 400 - 600 | 1,400 - 2,000 | 1.5 weeks | Medium |
| 600 - 1,000 | 2,000 - 2,700 | 2 weeks | High |
| 1,000 - 1,200 | 2,700 - 3,200 | 2 weeks | High |
| > 1,500 | On quote | 3 weeks+ | Very high |
You prioritize URLs that receive traffic or backlinks: they carry the value you must preserve at all costs.
The pitfalls that destroy rankings
Each of these mistakes means an avoidable ranking loss. The 4-week post-migration check exists precisely to catch them.
| Pitfall | Consequence | Fix |
|---|---|---|
| Redirect chain | Diluted equity, slow crawl | Redirect A straight to C |
| 302 instead of 301 | Value not passed | Force permanent 301 |
| Redirect loop | Page unreachable | Crawl audit before cutover |
| Redirect to homepage | Lost relevance | Redirect to the equivalent |
| Forgotten orphan URL | 404, lost traffic | Exhaustive inventory |
| Internal links not updated | Cascading redirects | Rewrite links hard-coded |
Tolerable traffic loss during stabilization is under 5%; beyond that, you reopen the plan.
Mini case study
Mr. Byrne, partner at a law firm in Dublin, is reworking a 640-URL site where 90 pages concentrate 80% of traffic. A redesign without a plan would have sent those 90 pages to 404, wiping out about 2,100 qualified visits per month. With a redirect plan at 2,100 EUR, every old URL points straight to its equivalent, with no chain. Result measured at 4 weeks: real loss of 3%, fully recovered by week six. The post-migration check intercepted 7 loops before they hit traffic.
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FAQ
301 or 302, what is the SEO difference?
The 301 is permanent and transfers the old page's SEO value. The 302 is temporary and does not durably pass authority: avoid it during a redesign.
What is a redirect chain?
It is when URL A redirects to B which redirects to C. Each hop dilutes equity and slows the crawl: you must redirect A straight to C.
How long should redirects stay in place?
At least 12 months, ideally permanently. Google can take several months to fully consolidate the signals.
Must every old URL be redirected?
Prioritize those with traffic or backlinks. URLs with no value or traffic can return a 410, but a 301 to the equivalent stays safer.
How do we verify everything works?
A full post-cutover crawl detects 404s, loops, and chains. You then monitor Search Console for 4 weeks.
Let's scope your project. Send us your URL count and target structure, and we will build a zero-loss 301 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.
