The verdict in three sentences
A traffic drop after a redesign is almost always technical: missing redirects, deindexed pages, broken structure or degraded Core Web Vitals. The 2026 technical SEO audit costs EUR 1,200 to 3,500 depending on site size, with a prioritized deliverable in 2 to 3 weeks. Properly implemented, it targets a gain of +20 to +45% organic traffic within 6 months: one of the best ROIs in B2B digital marketing.
What a serious technical audit contains
An audit is not an automated checklist. It cross-references crawl, log data, Search Console and human analysis to prioritize fixes by impact.
| Audited area | What we check | Typical weight |
|---|---|---|
| Indexing | Indexed vs deindexed pages, accidental noindex | Critical |
| Crawl & architecture | Depth, orphans, crawl budget | High |
| Redesign redirects | 301s, chains, surfaced 404s | Critical |
| Core Web Vitals | LCP, INP, CLS per template | High |
| Internal linking | PageRank distribution, anchors | Medium |
| Log analysis | Real Googlebot behavior | High |
| Structured data | Schema, rich results | Medium |
The key deliverable is a prioritized roadmap: what to fix first (high impact, low effort) and what can wait. Without prioritization, an audit remains an unusable list.
One-off audit or retainer: which format to choose
Two formats coexist in 2026, depending on your technical team's maturity.
| Format | Content | 2026 price (EUR) | For whom |
|---|---|---|---|
| Express audit | Site < 500 URLs, targeted diagnosis | 1,200 - 1,800 | SME, post-redesign urgency |
| Full audit | Crawl + logs + CWV + roadmap | 2,200 - 3,500 | Mid/large B2B site |
| Audit + 3-month support | Audit + fix implementation support | 4,500 - 7,000 | Team without in-house SEO |
| Monthly SEO retainer | Audit included + continuous optimization | 1,500 - 3,000/month | Durable strategy |
If your developers are autonomous, a one-off audit suffices. If you need implementation support, the retainer with follow-up secures the traffic gain.
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Mini case study
Sophie, marketing lead at a B2B SaaS vendor in Lyon, sees -38% organic traffic after a redesign. She commissions a full audit at EUR 2,800. The diagnosis reveals 140 missing 301 redirects and an LCP degraded to 4.2 s. After a 3-week fix, traffic returns to +12% of the initial level at month 3, then +34% at month 6. On traffic generating 40 leads/month worth EUR 300, this gain represents about 13 extra leads/month, i.e. EUR 3,900 of monthly value for an audit paid once.
FAQ
How long does a technical audit take? Between 2 and 3 weeks for a mid-sized B2B site. A very large site (> 10,000 URLs) or deep log analysis may take 4 weeks.
Does the audit include implementation? Not by default: the audit delivers the diagnosis and roadmap. Fixing is done by your teams or as a complementary engagement (retainer with support).
Why does traffic drop after a redesign? Most often due to missing redirects, changed URLs without 301s, pages set to noindex or a broken linking structure. The audit pinpoints the exact cause.
What traffic gain to expect? As a 2026 order of magnitude, +20 to +45% within 6 months when priority fixes are applied. The gain depends on the scale of the initial problems.
Is a free audit worth anything? Rarely: free audits are generic automated reports. A paid audit cross-references crawl, logs and human analysis, the only actionable combination.
Let's scope your project. Share your site size, CMS and context (redesign, migration, stagnation): we will price a prioritized audit. 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.
