Your traffic collapsed after a website redesign. Here is what went wrong

This is the most expensive mistake in web development, and the person paying for the site is the last to find out. The design is finished, everyone is pleased, and then two months later somebody notices the enquiries dried up.

We know this one particularly well. It happened to us, on our own site, during a rebuild. It is why redirect mapping is now the first thing we do on any project and the last thing we check before launch.

What actually happens

Google spent years learning your site. It knows that /our-services/seo/ answers a particular question, that eleven other websites link to it, and that people who click it tend to stay. That accumulated history is attached to the URL, not to the content.

Rebuild the site and that page becomes /services/seo. To a human it is obviously the same page. To Google it is one dead page and one brand new page with no history at all. Everything the old URL earned is discarded, and every external site linking to it is now linking to a 404.

One missing redirect is a nuisance. Twenty missing redirects across your main service pages is a business problem.

How to tell if this is your problem

• The drop started within days of launch, not gradually.
• Google Search Console shows a spike in "Not found (404)" pages.
• Searching site:yourdomain.com returns URLs that no longer work.
• Your rankings did not fall — the pages that held them simply vanished.

If instead the decline was slow and steady over months, this is probably not your cause and you should look at content and competitors rather than redirects.

The six rules we follow on every rebuild

1. Crawl the old site before switching anything off

Every indexed URL goes into a spreadsheet — not just the pages someone remembers. Old blog posts, category pages, PDF links, image pages. Use Search Console and a crawler, and check site: results for anything neither picked up.

2. Map old to new, one to one

Each old URL points to its closest new equivalent. A blanket redirect of everything to the homepage is the mistake people make when they run out of time, and it is barely better than doing nothing — it tells Google the old page is gone and its ranking value is not going anywhere in particular.

3. Use 301, never 302

A 301 means "permanently moved, transfer the value". A 302 means "temporary, hold on to the old one". Several content management systems default to 302, which leaves your rankings parked on pages that no longer exist. Check what yours is actually sending.

4. No redirect chains

Each old URL should reach its destination in one hop. A common accident is redirecting to the non-secure or non-trailing-slash version, which then redirects again to the final one. Every hop leaks a little authority, and across a whole site it adds up.

5. Test on staging, not in production

Every redirect gets checked before launch, confirming each one lands on a working page rather than another redirect. Finding this out from Search Console three weeks later is the expensive version.

6. Remove the noindex tag

Staging sites are built with search engines blocked so the half-finished version does not get indexed. Forgetting to remove that on launch day is more common than anyone admits, and it makes an otherwise perfect site invisible. Check it on launch day, then check it again the day after.

Recovering after the fact

If the damage is done, it is usually reversible. Map the old URLs, put the 301s in, remove any noindex, restore content that was cut, and resubmit your sitemap. Rankings often return within a few weeks, because they were never really lost — the pages holding them were just unreachable.

What does not work is reverting to the old site. That is simply a second migration, with a second set of risks.

The thing to ask before you commission a rebuild

Ask whoever is quoting: "will you produce a redirect map from every old URL, and can I see it before launch?" If the answer is vague, that is your warning. It is a few hours of unglamorous work that protects everything the site has earned.