Start with the fastest checks first

When rankings drop right after a website migration, I do not start by guessing about algorithm updates, backlinks, or broad “quality” issues. I start with the basics: can Google access and index the new site?

1. Check for a noindex tag

The first thing I check is whether the new site is accidentally set to noindex.

This is a common launch mistake, especially when a staging site gets pushed live and the staging settings come with it. If the site is noindex, it is usually an easy fix, but it can cause a major visibility drop if it stays live for too long.

2. Make sure the site actually works

Next, I check whether users and search engine bots can load and view the site properly. A migration can introduce simple but serious issues, including:

  • Pages returning server errors
  • Important templates breaking after launch
  • Navigation or internal links not working
  • Content not loading for Googlebot
  • Bugs that prevent pages from rendering correctly

If the website does not work, or if search engines cannot view important pages, rankings can fall quickly.

Decide whether it is a normal dip or a serious migration failure

Some movement after a migration can be normal. Google may need time to recrawl URLs, process redirects, and understand the new version of the site.

But a serious migration failure usually has clear warning signs.

Red flags I look for

  • All or most rankings disappear shortly after launch
  • Organic traffic drops sharply across the whole site
  • Google Search Console shows a major decline in clicks or impressions
  • Indexed pages drop significantly
  • Very few pages appear when you search site:example.com in Google
  • Important pages are returning 404s, redirecting incorrectly, or blocked from indexing

If we see those signals, I would not wait and hope rankings come back on their own. That usually means something in the migration broke and needs to be fixed.

Use your pre-migration data to find what changed

The best time to prepare for a rankings drop is before the migration launches. If we do not have clean benchmarks, it is much harder to know what actually changed.

At minimum, I want data from:

  • Google Search Console: clicks, impressions, average position, indexed pages, crawl issues, and query-level changes
  • Ahrefs: keyword rankings, backlink data, top pages, and period-over-period visibility changes

These tools help us compare performance before and after the migration instead of diagnosing based on guesses.

What to compare first

  • Which pages lost the most organic traffic?
  • Which queries lost impressions or rankings?
  • Which old URLs had backlinks or strong rankings before launch?
  • Are those old URLs still live, redirected, or missing?
  • Did indexed page counts drop after the migration?

A homepage might stay stable while service pages disappear. Blog traffic might drop because posts were removed. Product or category pages might lose visibility because URLs changed and redirects were missed. The data tells us where to look first.

Check whether important pages were removed

One of the most damaging migration mistakes is removing pages that were already ranking.

I worked on a migration recovery where a client had a different agency design and build a new website. During the launch, that agency removed most of the old pages, including service pages and blog posts. They only kept about 20% of the original pages.

The rankings drop was not mysterious. Google had been ranking URLs that no longer existed.

What we had to do

  • Identify the missing pages that had previously ranked
  • Add important service pages and blog posts back to the site
  • Confirm URLs stayed the same where possible
  • Set up proper redirects where URLs had changed
  • Monitor rankings and traffic as Google recrawled the restored pages

Recovery took about three months.

This is why content parity matters during a migration. If a page was bringing in traffic, rankings, leads, or backlinks, removing it should be a deliberate SEO decision. It should not happen just because the redesigned site has fewer pages.

Review redirects early

Redirects are one of the first things I check after indexation and access issues. The most common redirect mistake is forgetting to do them at all. The next most common mistake is not being organized enough.

What a good redirect process should cover

  • Every important old URL has a mapped destination
  • Changed URLs redirect to the closest relevant replacement
  • Old pages are not all redirected to the homepage
  • Redirects do not create long chains or loops
  • Redirect targets return a clean 200 status code
  • High-value pages with backlinks or rankings are prioritized

A missed redirect on a low-value page may not matter much. A missed redirect on a page with strong backlinks, leads, and top rankings can hurt quickly.

Redirect issues to look for

  • Old URLs returning 404 errors
  • Old URLs redirecting to unrelated pages
  • Service pages redirecting to the homepage instead of a matching service page
  • Blog posts redirecting to the blog index instead of a relevant article
  • Redirect chains that slow crawling and dilute signals
  • Redirect loops that prevent users and bots from reaching the page

For larger sites, ecommerce sites, and sites with complex URL structures, redirects need to be mapped before launch. Product pages, categories, discontinued products, location pages, blog posts, and filtered URLs all need a plan.

Prioritize fixes by speed and impact

After a rankings drop, it is tempting to fix everything at once. I prefer to work in order, starting with issues that are both serious and fast to correct.

Fix these first

  • Noindex tags: Remove accidental noindex directives from pages that should rank.
  • Robots.txt blocks: Make sure Google is not blocked from crawling important areas of the site.
  • Broken pages: Fix server errors, 404s, and broken templates on important URLs.
  • Redirect problems: Map old URLs to the most relevant new URLs.
  • Missing pages: Restore important pages that were removed during the migration.

Then move into deeper SEO checks

  • Internal links: Make sure important pages are still linked from navigation, body content, breadcrumbs, related posts, and category pages.
  • Canonical tags: Check that canonicals point to the correct indexable URL.
  • XML sitemaps: Include final indexable URLs, not old, redirected, noindex, or staging URLs.
  • Title tags and headings: Confirm key templates did not lose important on-page relevance.
  • JavaScript rendering: Make sure Google can see core content, links, and metadata.
  • Hreflang: For international sites, confirm language and country targeting did not break.

I usually start with easier, high-impact fixes like redirects and indexation problems, then move into more detailed areas like internal linking and template-level SEO.

Be careful with changes that add SEO risk

Some migration choices make rankings drops harder to diagnose because they change too many things at the same time.

If SEO performance matters, I would be cautious about doing these during the same launch:

  • Changing domains
  • Moving important sections to a subdomain
  • Removing large amounts of content
  • Changing the CMS
  • Changing URL structures
  • Redesigning page templates

None of these are impossible, but stacking them together increases risk. If rankings drop after a domain change, redesign, URL restructure, and content pruning all happen on the same day, we have to investigate every layer. That slows down recovery.

Look for patterns in the drop

A post-migration rankings drop is not always one sitewide problem. I like to segment the site by page type so we can see where the issue is concentrated.

How to segment the diagnosis

  • Blog posts: Were posts removed, noindexed, excluded from the sitemap, or buried in the new site structure?
  • Service pages: Did content, headings, title tags, URLs, redirects, or internal links change?
  • Product pages: Are products still indexable, available, and linked from categories?
  • Category pages: Did canonical rules, filters, pagination, or crawl paths change?
  • Location pages: Were local pages removed, consolidated, or redirected incorrectly?

What Search Console patterns can tell you

  • Clicks and impressions both dropped: Google may be showing the site less often.
  • Impressions are stable but clicks dropped: Rankings, titles, or SERP appearance may have changed.
  • Indexed pages declined: Look for noindex tags, robots blocks, canonical issues, removed pages, or crawl problems.
  • Only one section dropped: Focus on changes to that page type instead of treating the whole site as broken.

The faster we identify the pattern, the faster we can decide whether this is a temporary post-migration dip or a serious migration failure. If pages are missing, blocked, redirected poorly, or stripped of internal links, we should fix the cause instead of waiting for rankings to recover on their own.