The Ultimate SEO Website Migration Checklist: Expert Migration Tips to Protect Your Rankings, Traffic & Revenue

On paper, a website migration sounds simple. New site, new look, maybe a shiny new CMS. Then launch day arrives, traffic dips and keeps dipping, half the old URLs land on a 404 and someone in a meeting asks, quite reasonably, "what happened to Google?"

That is migration mayhem. The good news: a migration is not automatically bad for SEO. With proper planning, testing and monitoring you can protect the visibility you have spent years building, and sometimes improve it. This guide covers what to do before, during and after, with free checklists you can tick off, download or share.

What actually counts as a website migration?

In SEO terms, a migration is any significant change that affects how search engines find, crawl, understand or rank your site. That includes:

• Domain changes, such as oldbrand.ie to newbrand.com, or merging country domains.
• CMS or platform moves, such as WordPress to Shopify.
• Major redesigns, especially when templates, navigation and content change together.
• URL structure changes, such as removing /category/ from product URLs.
• HTTP to HTTPS, lower risk today but still needs redirects and checks.
• Merging websites, for example after an acquisition or rebrand.
• Rendering changes, such as moving to a JavaScript framework.

Risk depends on how much changes at once. HTTPS with identical URLs is fairly low risk. A new domain, new CMS, new URLs and rewritten content on the same weekend is high risk, because Google has to relearn almost everything. Change fewer things at once if you can.

Before the migration

Almost every migration disaster I have seen could have been prevented before launch. This is where you have the most control and the least pressure.

Agree the scope and the team

Write down what is moving, what is staying and why. Then make sure the right people are involved from the start:

• Project owner: owns the timeline, sign-off and the rollback decision.
• Developers: build redirects, templates and server rules.
• SEO: owns the URL inventory, redirect map and pre and post-launch checks.
• Content: protects priority pages and copy.
• Analytics: makes sure tracking and conversions survive the move.

Gather your migration documents

Before anything changes, build these. They are what you will check against later.

1. URL inventory. Crawl the site with Screaming Frog, Sitebulb or similar, then add URLs from XML sitemaps, analytics landing pages, Search Console and backlink tools.
2. SEO benchmarks. Organic sessions, top landing pages, conversions and revenue, priority rankings and indexed pages. Capture a few months to account for seasonality, and date the export.
3. Priority organic landing pages. The pages bringing in the most traffic, revenue and links. These get personal attention later.
4. Backlink data. Which old URLs have links from other sites, so none are left pointing at a 404.
5. Redirect map. Every old URL paired with its new home (more below).
6. Staging audit. A crawl of the new site before it goes live.
7. XML sitemaps. New sitemaps listing only indexable URLs that return a 200.
8. Tracking validation. Tags and conversion events tested on staging, and Search Console access confirmed for old and new properties.

Build your URL redirect map

When a URL changes, it should 301 redirect to the most relevant equivalent page. Google explains this in its guidance on redirects and Google Search.

• Map one to one wherever possible. Keep URLs the same where you can: the safest redirect is the one you never needed.
• Avoid redirect chains. One hop, old to final destination.
• Do not redirect everything to the homepage. Redirecting every old URL to the homepage isn't a shortcut worth taking. When the destination isn't relevant to the original page, Google may treat the redirect as a soft 404, meaning ranking signals might not transfer as intended. Wherever possible, redirect old URLs to their closest relevant equivalent.

Example, correct: /shop/blue-running-shoes 301 to /running/shoes/blue-running-shoes. Same product, new address.

Example, incorrect: /shop/blue-running-shoes 301 to the homepage. Tidy for the developer, useless for the customer and for Google.

If a page genuinely has no replacement, a 404 or 410 is honest. Losing an important page without a plan is the problem, not every 404.

Protect your valuable content

A technical migration is not the moment to delete half the blog or rewrite every title "while we are at it". Keep valuable content, headings and metadata close to the original, and save big content changes for later.

For every page you plan to remove, ask: does it get organic traffic, does it have backlinks, does it help customers convert? If yes, keep it, merge and redirect it, or have a very good reason.

Test the staging site properly

Staging is where problems are still cheap. Crawl it and check:

• robots.txt and noindex. Staging is usually blocked on purpose, and that block must not travel to the live site.
• Internal links, canonicals and sitemaps point to the new URLs, never the old ones or the staging domain. See Google's sitemaps overview.
• Rendering on JavaScript-heavy sites: can a crawler see your content and links?
• Structured data, hreflang, titles and meta descriptions.
• A sample of redirects from your map.

Pick a sensible launch date

Avoid your busiest season, a big sale or a bank holiday weekend. Launch early in the week, in working hours, when developers and SEO support can fix things fast. A Friday evening launch usually means problems sit unfixed all weekend while Google happily crawls them. Agree a rollback plan, and who makes that call, in advance.

Launch Day: What Absolutely Must Work?

If your preparation was solid, today is about checking that what you planned is what actually happened. Keep Google's guide to site moves with URL changes open in a tab.

Critical issues

• Important pages inaccessible or returning errors.
• A sitewide noindex or robots.txt block. Google explains how noindex works in its guide to blocking indexing.
• Major broken redirects, loops or chains.
• Severe server errors.
• Significant conversion journey failures: checkout, forms, bookings.

Important fixes

• Minor metadata issues.
• Isolated broken links.
• Non-critical structured data issues.

Severity depends on the scale and impact of the issue: one broken link on a minor page is not the same as one on your top revenue page. Critical failures should be escalated immediately and the agreed rollback plan evaluated, not left until Monday.

Your launch-day run-through

1. Crawl your list of old URLs and confirm each returns a single 301 to the right page.
2. Check priority pages return a 200.
3. Check robots.txt and look for leftover noindex tags.
4. Check canonicals and internal links on key templates.
5. Submit updated XML sitemaps in Search Console.
6. Complete a real test enquiry or purchase to confirm tracking.
7. Test on mobile and walk through critical journeys.

Moving to a new domain? Use the Change of Address tool in Search Console. It is only for domain or subdomain moves, not a CMS change or new URLs on the same domain.

After the migration

The migration is not done when the new site goes live. The weeks afterwards are when you find out how Google has really taken it.

Your monitoring schedule

• First 24 hours: test redirects, priority URLs, indexability and tracking.
• First week: review Search Console, crawl findings and landing page behaviour.
• Weeks 2 to 4: monitor visibility, rankings, conversions and unresolved issues.
• Following months: track longer-term performance and investigate persistent problems. Keep redirects in place for the long term; Google recommends at least a year.

Every site recovers at its own pace, so compare against your benchmarks week by week rather than panicking over a single day.

What a normal dip looks like

Usually fine: a small dip while Google recrawls, with priority rankings broadly holding. Investigate now: a steep drop on specific templates, such as all product pages. That points to something technical, the kind of issue covered by a technical SEO audit.

Example indexing mistake: a new blog template ships with a leftover noindex tag. Traffic to the homepage looks fine, but within a fortnight Search Console shows blog URLs moving to "Excluded by noindex tag". The fix is one line, but only if someone is watching.

Review Search Console and indexing

Watch the page indexing reports for jumps in excluded pages, "crawled, currently not indexed" or "page with redirect". If important pages drop out of the index, my guide to common indexing issues and how to fix them walks through the likely causes.

Find and fix broken URLs

Look for 404s in Search Console, your crawler and server logs, especially old URLs that still get visits or have backlinks. Add missing redirects and fix chains that crept in.

Update the links you control

Redirects help, but links you own should point straight to the new URLs: social profiles, email signatures and templates, Google Business Profile, directory listings, partner sites, microsites and intranets.

Document what happened

Record what changed, when, what broke and how it was fixed. The next person to run a migration will be very grateful.

Migration Mistakes That Can Ruin Your SEO

1. Redirecting everything to the homepage. Irrelevant redirects can be treated as soft 404s, so ranking signals may not transfer. Map each page to its closest equivalent.

2. Launching with noindex still on. The staging setting quietly removes your site from Google. Check it on launch day, then check again.

3. Deleting valuable content. Pages that brought traffic and links vanish because they "looked old". Review performance before cutting anything.

4. Forgetting internal links. Every click bounces through a redirect and signals weaken. Update links at source.

5. Ignoring hreflang. The wrong country version starts ranking in the wrong market. Test hreflang on staging.

6. Not monitoring afterwards. Problems spotted in week one are cheap to fix; in month six they usually are not. Follow the schedule above.

Planning a Website Migration?

Migrations are not inherently bad for SEO. What causes the damage is poor planning, rushed decisions and missing checks. Getting the foundations right before launch is far easier than repairing the damage afterwards.

I can help you protect the organic visibility you've worked hard to build, from pre-launch planning and redirect mapping through to post-launch monitoring. Take a look at my SEO migration service, browse my portfolio or get in touch.

Fancy one more go? Play Migration Mayhem