The 5 mistakes to avoid when redesigning your website

Key takeaway - A poorly prepared website redesign can result in a 50-70% loss of organic traffic according to Ahrefs and Content Powered, a risk that can be avoided through a preliminary SEO audit, a 301 redirect strategy, and progressive migration of high-performing content.

Introduction: A Redesign Can Destroy Your SEO

Redesigning your website is often exciting: new design, better features, modernized image. But behind this promise lies a major risk: losing the organic search rankings you've built over years.

The numbers are alarming. According to Ahrefs, a site that deleted 15% of its pages during a redesign lost nearly 50% of its organic traffic. A study by Content Powered reports 60-70% traffic drops after poorly prepared redesigns.

The good news? These disasters are avoidable. Here are the 5 most common mistakes during a website redesign, and how to avoid them.

Mistake #1: Neglecting the SEO Audit Before Redesign

The Problem

Too many companies launch into a redesign without analyzing what works on their current site. Result: they delete high-performing pages, modify well-ranked URLs, and lose years of SEO work.

According to Luneos, treating SEO as an afterthought is the most frequent mistake.

The Consequences

• Deletion of pages generating organic traffic
• Loss of well-positioned keywords
• Destruction of internal linking
• Sudden traffic drop (sometimes irreversible)

The Solution

Before starting the redesign, conduct a complete audit:

1. Identify your top-performing pages with Google Analytics and Search Console
2. List your ranked keywords and their current positions
3. Map your backlinks with Ahrefs, Semrush, or Moz
4. Analyze your internal linking and most-linked pages
5. Document your current URL structure

Golden rule: never delete a page that generates traffic without having a redirect strategy.

Mistake #2: Forgetting 301 Redirects

The Problem

Changing your page URLs without implementing redirects is a fatal mistake. Your old URLs, indexed by Google and shared across the web, will lead to 404 pages.

According to Agence Churchill, 301 redirects are crucial for transferring accumulated "SEO juice" to new URLs.

The Consequences

• Massive 404 errors: poor user experience and negative signal for Google
• Loss of backlinks: all external links point to non-existent pages
• Deindexation: Google removes 404 pages from its index
• Traffic drop: can reach 60-70% in some cases

The Solution

Create a comprehensive redirect plan:

Redirect checklist:

• ✅ Map 100% of old URLs to new ones
• ✅ Use 301 (permanent) redirects, not 302
• ✅ Avoid redirect chains (A → B → C)
• ✅ Test each redirect before going live
• ✅ Keep redirects active for at least 1 year

Mistake #3: Changing Site Structure Without Strategy

The Problem

A redesign is often an opportunity to "tidy up" the site: merge categories, reorganize menus, simplify the architecture. But every change impacts SEO.

The Consequences

• Disorganized internal linking: loss of "SEO juice" between pages
• Depth changes: a page moving from level 2 to level 4 loses authority
• Confusion for Google: the crawler must relearn the structure
• Loss of siloing: destruction of thematic coherence

The Solution

Plan your new architecture with SEO in mind:

1. Keep pillar pages at low depth (max 3 clicks from homepage)
2. Maintain thematic silos: group content by topic
3. Preserve internal linking: links between pages should remain logical
4. Document changes: create an old → new mapping

Example of optimized structure:

Homepage
├── Services (level 1)
│   ├── Website Creation (level 2)
│   ├── Mobile App (level 2)
│   └── SEO (level 2)
├── Blog (level 1)
│   ├── Category 1 (level 2)
│   │   └── Articles (level 3)
│   └── Category 2 (level 2)
└── Contact (level 1)

Mistake #4: Ignoring Technical Aspects Post-Migration

The Problem

The new site is live, it looks beautiful, everything seems to work... but no one checked the technical aspects. Weeks pass, traffic drops, and by the time you notice, the damage is done.

According to Première Page, many sites launch their redesign without a post-migration technical audit, leaving critical errors undetected.

Common Technical Errors

The Solution

Post-migration checklist (check within 48h):

• ✅ Check robots.txt: no important sections blocked
• ✅ Control meta tags: no accidental noindex
• ✅ Submit new sitemap to Google Search Console
• ✅ Test Core Web Vitals with PageSpeed Insights
• ✅ Scan for 404 errors with Screaming Frog or Search Console
• ✅ Verify HTTPS: all pages with SSL
• ✅ Check duplicate content: correct canonical tags

Essential tool: set up alerts in Google Search Console to be notified immediately of any issues.

Mistake #5: Not Planning a Monitoring Period

The Problem

A temporary traffic drop is normal after migration (10-15% for a few days). But without monitoring, it's impossible to distinguish a normal dip from a serious problem.

According to Sérieux Design, a drop exceeding 30% or persisting beyond 3 weeks indicates a problem requiring urgent correction.

Consequences of Lack of Monitoring

• Problems undetected for weeks
• Traffic loss becoming permanent
• Difficulty identifying the cause after the fact
• Multiplied correction costs

The Solution

Post-redesign monitoring plan:

KPIs to monitor:

• Organic traffic (Google Analytics)
• Impressions and clicks (Search Console)
• Target keyword positions
• Bounce rate and time on page
• Crawl errors (Search Console)
• Core Web Vitals

Complete Checklist: Redesign Without Losing Your SEO

Before the Redesign

• Complete SEO audit of current site
• List of high-performing pages to keep
• Export of keywords and positions
• Backlink inventory
• URL mapping (old → new)
• 301 redirect plan

During the Redesign

• Preserve optimized title and meta description tags
• Keep high-performing content
• Maintain URL structure if possible
• Implement 301 redirects
• Test in staging environment

After the Redesign

• Check robots.txt and meta robots
• Submit new sitemap
• Monitor key page indexing
• Watch for 404 errors
• Monitor traffic daily (2-4 weeks)
• Analyze Core Web Vitals

FAQ

How long does the traffic drop last after a redesign?

A 10-15% drop for 1-2 weeks is normal, while Google reindexes the site. If the drop exceeds 30% or persists more than 3 weeks, there's likely a technical problem to fix.

Can you change CMS without losing SEO?

Yes, provided you follow best practices: keep URL structure (or 301 redirects), migrate optimized content, and maintain technical performance. A well-prepared WordPress → Next.js migration can even improve your SEO thanks to performance gains.

Should you notify Google of a redesign?

Not directly, but you should submit your new sitemap via Search Console and use the "URL Inspection" tool to request indexing of key pages. Google will naturally discover changes through crawling.

What to do if traffic collapses after redesign?

1. Immediately check 404 errors in Search Console
2. Control robots.txt file and noindex tags
3. Validate that 301 redirects work
4. Resubmit your sitemap
5. If the problem persists, call an SEO expert

Conclusion: Plan Ahead for a Successful Redesign

A website redesign is an exciting project, but SEO should never be an afterthought. Companies that lose 50, 60, or even 70% of their traffic after migration have all made the same mistakes: lack of preparation, forgotten redirects, technical negligence.

By following the best practices in this guide, you can redesign your site without sacrificing your search rankings - and even improve them through technical optimizations.

Planning a Redesign? Let's Talk.

At Neodigit, we support companies in their redesign projects with an SEO-first approach. Our methodology:

• Complete SEO audit before any development
• Detailed migration plan with URL mapping
• Systematic 301 redirects, tested and verified
• Post-launch monitoring for 30 days
• Contractual SEO continuity guarantee

We've supported dozens of migrations without traffic loss - and often with significant gains thanks to performance improvements.

Ready to redesign your site without risk? Let's discuss your project or request a free audit.