Our Take On Website Migration Best Practices (Complete Guide)

Key takeaways

• A migration’s biggest risk is to your SEO and most of that risk is preventable with planning. The work that protects your rankings (auditing, benchmarking, redirect mapping) happens before any technical change is made, not after launch.
• Redirects are the single most important factor. A complete, accurate set of 301 redirects mapping every old URL to its closest new equivalent is what carries your hard-won search visibility across to the new site. Get this wrong and you can lose years of accumulated value.
• Test everything on staging, then monitor closely once live. Problems are far cheaper to fix before a single visitor or search engine sees the new site, and a temporary dip afterward is normal: expect a few weeks to a couple of months of fluctuation before things stabilize.
• The smoothest migrations are a team effort. SEOs and developers working side by side from the start (not in sequence) is what prevents the classic, costly mistakes, and every migration is different, so treat best practices as a framework to adapt, not a rigid checklist.

Whether you’re rebranding, upgrading your CMS, changing domains or improving your site’s architecture, a website migration is a significant undertaking. While migrations can unlock better performance, a faster site and a stronger brand presence, they also come with real risks, especially when it comes to SEO.

Over the years, the SEO experts at Bloom have successfully completed many website migrations for clients across a variety of industries. It’s safe to say that we’ve learned a lot along the way, and now know what truly matters and what doesn’t when undertaking a migration.

In our experience, a well-executed migration can be virtually seamless. With the right planning, you can preserve your search visibility and ensure a smooth transition for both users and search engines.

It’s worth being honest up front, though: every migration is different. The right approach depends on your tech stack, the size of your website, your CMS, your page templates and countless other factors. This guide covers the website migration best practices that apply to most projects, but think of them as a framework to adapt, not a rigid checklist that fits every situation identically.

One principle runs through everything below: the more elements you change at once (CMS, design, URL structure, domain, hosting, etc.), the more performance fluctuation you should generally expect and the harder it becomes to diagnose what caused a problem if something goes wrong. You don’t necessarily have to change one thing at a time; plenty of “all-in-one” migrations recover well. But going in with that awareness helps you set expectations and plan your monitoring accordingly.

Our Clients Often Ask: What Is Website Migration?

A website migration is the process of making significant changes to a website’s structure, platform, design, content and/or domain.

Common types of migrations include:

• Moving to a new content management system (CMS)
• Changing domains
• Redesigning the website
• Restructuring URLs
• Changing hosts

Organizations typically undertake migrations to improve site performance, enhance user experience, support business growth, strengthen their brand presence or adopt more modern and scalable technologies. A migration is also a natural opportunity to improve technical foundations that affect SEO, such as page speed/Core Web Vitals, mobile responsiveness, site architecture, structured data and many more elements. It’s worth treating it as a chance to move forward, not just a box to move from A to B.

Our 3-Phase Website Migration Framework

Phase 1: Build a detailed migration plan

Successful website migrations begin long before any technical changes are made.

1. Define your goals and objectives

Start by defining the purpose of the migration and identifying your desired outcomes. Clear objectives guide decision-making throughout the project and give you a way to measure success after launch.

2. Create a content inventory

Document your current website, including pages, media assets, downloadable files and other key content. A complete inventory makes it far easier to verify that everything transferred correctly and to spot anything missing after the migration.

3. Decide what content to keep, prune or merge

A migration is a natural moment to clean house, but every change should be deliberate. Using your content inventory, give each page a disposition: keep, prune (remove low-value pages) or merge (consolidate thin pages into one stronger page). 

Whatever you prune or merge still needs a 301 redirect (more on that in section “8. Plan your redirect strategy” of this article) to its most relevant surviving page, never a silent deletion or a dump to the homepage.

4. Audit your existing website

Before the migration begins, conduct a thorough audit of your existing site. This means you should:

• Review your current SEO performance and analyze your backlink profile.
• Establish benchmarks for traffic and rankings to compare against later.
• Identify which pages generate the most traffic and earn the most external links, so you can prioritize their redirects.

If you’d like help here, see our SEO audit services.

5. Review accessibility requirements

Perform an accessibility assessment to ensure your new website remains compliant and usable for everyone. Addressing accessibility early prevents costly issues later in the migration process.

6. Prepare for the transition

Create a complete backup of your website and database before making any changes. To minimize disruption, schedule the migration during a period of lower traffic, when fewer users are likely to be affected. If possible, a slower business period is often the ideal window.

7. Prevent premature indexing

Keep search engines from crawling and indexing the new website while it’s still being built and tested. A word of caution, though: the same controls that protect a staging site (a noindex tag or a robots.txt disallow rule) can be catastrophic if they accidentally ship to the live site. Make removing them a required step at launch, not an afterthought.

8. Plan your redirect strategy

This is the single most important SEO element of any migration and it deserves real attention. A redirect tells search engines and users that a page has moved, passing along the authority the old page had earned. Get it right and your rankings largely carry over. Get it wrong and you can lose years of accumulated SEO value. Best practices:

• Use 301 (permanent) redirects, not 302 (temporary) ones. A 301 passes ranking signals to the new URL. A 302 tells search engines the change is temporary, so they may keep the old URL indexed.
• Map old URLs to new ones on a 1:1 basis. Each old URL should point to the closest equivalent page on the new site.
• Avoid redirect chains and loops. A redirect chain (old URL to URL A to URL B to final new URL) wastes crawl budget and dilutes link equity. Redirect straight to the final destination.
• Don’t redirect everything to the homepage. This is one of the most common and damaging mistakes. Search engines often treat a redirect to an unrelated homepage as a soft 404 and the page’s value is lost. Always redirect to the most relevant page.
• Keep your redirect map as a documented deliverable. It’s your reference during testing and your audit trail if something goes wrong.

Finally, remember that redirects are rarely perfect on day one. Once the site is live, monitor 404 errors closely (in Google Search Console and, where available, your server access logs). New 404s will reveal old URLs you missed, so you can add the necessary 301 redirects as they surface.

If you wish to have more information on planning your redirects correctly, Google’s official documentation (specifically section 3 “Prepare URL mapping”) is a great resource to look into.

9. Preserve your internal linking and URL structure

Migrations are a common point where internal links silently break, leaving important pages orphaned (no longer linked from anywhere) and harder for both users and search engines to find. Two things to protect:

• Internal links: make sure every page you want indexed stays easy to find through internal links, whether that’s the navigation menu, breadcrumbs or in-content links.
• URLs: keep them clean and logical, but don’t change them without a reason. Every URL you change is another redirect to manage and another small risk to your rankings, so change them only where there’s a clear benefit.

10. Handle canonical tags and hreflang

These two tags both tell search engines how to interpret your pages and migrations are a common point where they break. Take a moment to check each one applies correctly on the new site.

• Canonical tags: tells search engines which version of a page is the primary one, which helps prevent the duplicate-content issues that often crop up during a migration. Make sure yours point to the correct new URLs.
• Hreflang: only applies if your site serves multiple languages or regions (for example, French and English versions of the same pages). If that’s your situation, confirm the tags still point to the correct new URLs for each language version, since they break easily during a migration. If your site is single-language, you can safely skip this.

Phase 2: Test before launch

Thorough testing is what separates a smooth migration from a stressful one. The goal is simple: find and fix problems while you still can, before a single visitor or search engine sees the new site.

1. Use a staging environment

Test the new website thoroughly in a staging environment before sending any real visitors to it. Staging lets you catch and resolve issues in private, without affecting your live site or your rankings.

2. Compare the old and new sites side by side

Confirm that nothing was lost or altered unintentionally in the move. Check that the following carried over correctly:

• Page content, headings and images
• Page titles and meta descriptions
• Downloadable files and media assets
• URLs (and that they match your redirect map)

If you’re intentionally pruning or merging content, the new site won’t match the old one page-for-page and that’s fine. Check those pages against your keep/prune/merge decisions so deliberate changes aren’t mistaken for content lost by accident. Then, make sure each pruned or merged page still gets a 301 redirect to its most relevant surviving page.

3. Crawl the staging site

Run a full crawl of the staging environment with a tool such as Screaming Frog. A crawl surfaces problems that are easy to miss by clicking around manually, including broken links, missing or duplicate metadata, incorrect canonical tags and orphaned pages. Fixing them now is far cheaper and has far less impact on SEO performance than fixing them after launch.

4. Validate your redirects before go-live

Don’t wait until launch day to find out your redirect map has gaps. Test a representative sample of old URLs against the map to confirm each one lands on the right new page with a 301, with no chains or loops. The more redirects you’re managing, the more this pre-launch check matters.

5. Test core functionalities

Verify that every essential feature works correctly, including:

• Buttons, forms and other interactive elements
• On-site search
• Checkout and payment flows (for ecommerce)
• Navigation menus and internal links

6. Check mobile and cross-device performance 

Users access websites from a wide range of devices, so make sure the new site is fully responsive and displays correctly across desktop, tablet and mobile.

7. Identify remaining technical issues

Lean on your staging crawl, along with tools like Google’s Lighthouse or PageSpeed Insights, to catch any remaining broken links, redirect problems, metadata issues or slow pages before the site goes live.

Phase 3: Monitor and optimize after launch

1. Submit your XML sitemap

Once the migration is complete, submit your updated XML sitemap to Google Search Console and Bing Webmaster Tools. This helps search engines discover and index your new URLs more efficiently.

2. Review crawling and indexing settings

Check your robots.txt file and remove any temporary restrictions used during development or staging. Confirm that search engines can access the pages you want indexed and that no lingering noindex tags or authentication barriers remain.

3. Run a post-migration site crawl

Conduct a full crawl of the new live site to catch broken links, error pages and other technical SEO problems that may have emerged within it.

4. Verify your redirects are live

Separately, crawl your list of old URLs (your redirect map) to confirm each one returns a 301 to the right new page, with no chains, loops or 404s. This is a different crawl from the one above: the site crawl follows links within the new site, while this one checks that the old URLs still resolve correctly. Keep watching for new 404s in the weeks after launch, as they’ll reveal any old URLs you missed.

5. Verify your analytics and tracking continuity

A migration shouldn’t cost you your measurement. Two checks matter most:

• GA4: confirm your tags are present and firing on the new site so you don’t lose data.
• Google Search Console: the main goal is to verify that data is still populating. Depending on how your property was set up and whether your domain has changed, you may or may not need to reconfigure it, so don’t assume it carried over automatically. If you’ve changed domains, use the Change of Address tool to help Google process the move.

6. Update external links and listings

Point the references you control at your new URLs:

• Update links on your social media profiles, partner websites and other external sources.
• Reclaim or redirect important backlinks where possible.
• If you have a Google Business Profile or other local listings, update those too, especially if your domain has changed, so your business information stays accurate and consistent.

7. Monitor performance metrics

Compare post-migration results against the benchmarks you established before launch. Keep an eye on site speed, organic traffic, page views, conversions and search rankings, using tools like Google Analytics and Google Search Console. 

Just keep in mind that not every shift after launch can be confidently attributed to the migration process: seasonality, increased competition, algorithm updates, paid-media changes or wider market trends can all move these numbers too. Factor that context in before concluding the migration itself is responsible for a change.

8. Expect (and plan for) a temporary dip

Even a flawless migration often sees some fluctuation in traffic and rankings, typically for a few weeks and sometimes up to a couple of months, as search engines recrawl and reprocess the new site. This is normal.

• What’s normal: a dip that starts recovering within that window.
• What’s a red flag: a decline that keeps going with no sign of recovery or pages dropping out of the index entirely. Both point to a technical problem worth investigating.

Because some short-term softness in organic traffic is common, this can also be a sensible time, on a case-by-case basis, to lean a little harder on other channels such as paid search or email to help bridge the gap. And as noted earlier, scheduling the migration during a slower business period is the best way to keep any dip from stinging.

9. Keep optimizing

The weeks following a migration are critical. Ongoing monitoring lets you catch issues quickly, measure the success of the migration and make adjustments that improve performance over time.

Pre-launch migration checklist

Use this as a high-level checklist before you go live:

• Migration goals and success metrics defined
• Full content inventory completed
• Keep, prune or merge decision made for every page
• Pre-migration SEO benchmarks captured (traffic, rankings, backlinks)
• Complete site and database backup taken
• 301 redirect map built (1:1, no chains, no homepage dumping)
• Redirects validated on staging
• Internal links are functioning properly (no orphaned pages)
• Canonical tags (and hreflang, if applicable) verified
• Staging site fully tested and crawled
• Indexing controls ready to remove at launch (no stray noindex or robots.txt disallow shipping live)
• Analytics (GA4) and Search Console ready for the new site
• XML sitemap updated and ready to submit
• Rollback plan agreed in case something goes wrong (website backup could be very helpful here)

Why SEO And Developers Need To Work Together

We’ve been doing this for over 20 years, so you can trust us when we say that the smoothest migrations all have one thing in common: SEOs and web developers need to work side by side from the very start, not in sequence. The two roles own different pieces of the project:

• Developers own the technical build, the staging environment and the launch itself.
• SEOs own the redirect map, the URL and metadata decisions, the crawl and indexing checks and the post-launch monitoring.

When those two tracks run in isolation, the classic problems appear: redirects get forgotten, a staging noindex ships to production or URLs change without anyone mapping them.

In practice, good collaboration looks like:

• Reviewing the redirect map together before launch
• Agreeing on URL structure early
• Testing the staging site as a team
• And many other decisions

It also means looping in the wider group (content, marketing and leadership) so everyone is aligned on timing and on what happens if something goes wrong.

That last point is worth its own line: agree on a rollback plan before you launch, so you know how you’d revert to the old site if a serious issue surfaces. You’ll almost certainly never use it, but having it removes the pressure from launch day.

Migrate With Confidence, Not Crossed Fingers

A website migration touches your platform, your content and your hard-won search visibility all at once, which is exactly why a disciplined approach matters. Plan thoroughly, test everything before launch and monitor closely afterward and you turn a high-risk project into a controlled, predictable one. Every site is different, but those three phases hold true across them all.

A website migration is a significant investment of time and resources, but with the right partner, it doesn’t have to be overwhelming. Our team can help you plan, execute and optimize your migration to minimize risk and maximize results.

Contact us to get started.