Top 10 mistakes in site migration

At some point in the lifespan of most websites, the foundation on which they were originally built may no longer be sufficient to support growth.

Perhaps you started with a small WooCommerce store on WordPress but later realized that a Magento solution offers better product and warehouse management.

If you’ve reached that stage, you may need to decide whether a site migration—moving your website to a new CMS—makes sense. Another common scenario is securing your dream domain, which better aligns your brand identity with your URLs.

In both cases, you face several pitfalls and challenges that must be handled correctly to prevent losing the organic authority you’ve built over time.

In this article, our Head of SEO, Lars, highlights the most common challenges during a site migration. Not every issue may apply to your migration, but failing to address even one of them could lead to significant problems.

- Table of contents

Missing 301 redirects from old to new URLs
Reduced page speed after migration
Forgotten noindex tags or blocked crawling
Major changes in URL structure
Duplicate content after migration
Loss of backlinks and link equity
Poor internal linking after migration
Traffic drop after migration
Errors in structured data (Schema Markup)
Failure to update Google Search Console & Bing Webmaster Tools

1. Missing 301 redirects from old to new URLs

Problem: If old URLs are not properly redirected to new ones, you risk losing rankings and traffic.

Solution:

Create a redirect mapping from old to new URLs and implement 301 redirects.
Use tools like Screaming Frog to crawl both old and new URLs to ensure everything is mapped correctly.
Test redirects thoroughly using Google Search Console and server log files.

2. Reduced page speed after migration

Problem: New pages may load more slowly due to heavier code, poorly optimized images, or inferior hosting.

Solution:

Test speed with Google PageSpeed Insights before and after migration.
Compress images, minify CSS/JS, and enable browser caching.
Use a Content Delivery Network (CDN) to speed up content delivery.

3. Forgotten noindex tags or blocked crawling

Problem: If noindex tags are left on new pages or if robots.txt blocks Google, your pages will disappear from search results.

Solution:

Ensure that noindex tags are removed on the live site.
Check robots.txt for unintended blockages.
Use Google Search Console to verify that Google can crawl and index your new pages.

4. Major changes in URL structure

Problem: If the URL structure is drastically changed without proper handling, rankings can drop significantly.

Solution:

Retain old URLs where possible, especially for key pages.
If changes are necessary, implement 301 redirects from old to new URLs.
Use internal linking to reinforce the new URL structure.

5. Duplicate content after migration

Problem: If old and new versions of a site exist (e.g., www vs. non-www, HTTP vs. HTTPS, staging versions), Google may perceive them as duplicate content.

Solution:

Ensure there is only one official site version using canonical tags.
Set up 301 redirects for all old versions to point to the correct new version.
Remove or block any staging pages from indexing.

6. Loss of backlinks and link equity

Problem: If pages with strong backlinks disappear without redirection, valuable authority is lost.

Solution:

Identify pages with the most backlinks using tools like Ahrefs, Majestic, or Google Search Console.
Redirect these pages to relevant new pages using 301 redirects.
Reach out to important backlink sources and request they update their links.

7. Poor internal linking after migration

Problem: If internal links still point to old URLs, both Google and users may become confused.

Solution:

Update all internal links to point to new URLs—consider using a database-wide search.
Use Screaming Frog to identify internal links pointing to old pages.
Ensure that the XML sitemap contains only the new URLs, not the old ones.

8. Traffic drop after migration

Problem: A temporary traffic dip is common, but if it persists, SEO problems may be to blame.

Solution:

Monitor Google Search Console for crawl errors and indexing issues.
Ensure key pages are recrawled and indexed quickly—request indexing in Search Console.
Check Google Analytics to identify which pages lost the most traffic and adjust accordingly.

9. Errors in structured data (Schema Markup)

Problem: After migration, structured data may disappear or become corrupted, reducing click-through rates (CTR) in search results.

Solution:

Validate structured data using Google’s Rich Results Test after migration.
Implement proper Schema Markup (e.g., product data, FAQs, reviews).
Update JSON-LD or Microdata if necessary.

10. Failure to update Google Search Console & Bing Webmaster Tools

Problem: If you don’t update Search Console, Google may struggle to find the new pages.

Solution:

Submit a new XML sitemap in Google Search Console.
Use the “Change of Address” tool in Search Console if changing domains.
Monitor crawl errors, indexing, and performance post-migration.

Site migration checklist

✔️ Crawl the old site with Screaming Frog to document the existing structure.

✔️ Map redirects from old to new URLs.

✔️ Test redirects using Screaming Frog or HTTP Status Code Checker.

✔️ Update internal links, XML sitemaps, and robots.txt.

✔️ Remove noindex tags and avoid accidentally blocking new pages.

✔️ Monitor traffic and rankings in Google Search Console and Google Analytics.

A well-executed site migration can boost your SEO, but without proper planning, it can seriously harm your visibility.

Have an upcoming site migration?

Reach out to Lars if you have an upcoming site migration and need expert guidance—we’ll help you navigate the process successfully!

Lars Thrane

Head of SEO

lars@iternumdigital.com

+4532121100

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