How to succeed with your SEO migration

New CMS, redesign, evolution of the site structure: a site migration can represent a significant risk for your organic traffic - and therefore for your turnover - if it is not well anticipated.

Conversely, when well prepared, it can become a real opportunity for SEO growth. It is indeed the ideal time to correct existing technical problems, strengthen internal linking, improve web performance and user experience, or optimize certain essential SEO elements. Provided, of course, that SEO is integrated as far upstream as possible in your migration project, and not just as a simple checkbox on a checklist.

From analyzing the existing site to post-migration monitoring, including setting up the redirection plan, here is how to successfully complete your SEO migration step by step.

What is an SEO migration?

An SEO migration refers to all the actions taken to deeply modify a website while preserving - or even improving - its organic visibility on Google (positioning on targeted keywords, organic traffic). It occurs during a CMS change, a website redesign, a site structure reorganization, or a switch to a new domain name.

Concretely, the SEO migration process consists of anticipating the various impacts of the changes made to your website to preserve SEO performance:

setting up redirections from old URLs to new ones;
maintaining existing optimizations;
opportunity to improve what already exists (optimization of page title and meta description, implementation of consistent and optimized h1..hn tagging, internal linking, technical optimizations), etc.

What are the challenges and risks of an SEO migration?

A poorly prepared or poorly executed SEO migration risks causing your organic traffic to collapse and, with it, your turnover. Your current site probably generates organic traffic and already possesses a certain SEO authority. A migration without anticipation carries the risk:

that your existing pages return a 404 error if you modified their URL, for lack of having set up the necessary redirections
that your new pages are not optimized, for lack of having carried over or re-implemented existing optimizations (title, meta description, tagging, content, etc.)
that your internal linking is not effective, possibly resulting in orphan pages (which receive no internal links from the rest of the site structure)
that pages that received backlinks (links from other sites), and therefore SEO authority, are now in 404 error, and this authority is consequently lost
that your internal links are broken if you have not done what is necessary
that technical issues have a negative impact on how your site is perceived by Google

In any case, this generally results in a drop in ranking on your keywords, and therefore a loss of organic traffic - with, of course, an impact on conversions or turnover.

Conversely, a migration can be an opportunity to generate SEO growth:

Correction of existing technical problems
Optimization of what exists: internal linking, title, tagging, etc.
Publishing new content pages
Improvement of the user experience (UX)
Improvement of web performance

To make your migration a real growth lever for your organic traffic, SEO challenges and issues must be integrated as far upstream as possible in the project.

What are the different steps of an SEO migration?

Analyzing the existing site

An indispensable prerequisite for any SEO migration: taking stock of what exists. Start by doing a complete crawl of your site, for example with a tool like Screaming Frog, Oncrawl, or the redirection.io crawler, then cross-reference and supplement the crawl data with:

Your Google Search Console data (clicks, impressions)
Your analytics data (traffic, conversions, turnover)
The URLs listed in your XML sitemap
Your URLs that receive backlinks
Data from SEO visibility tools (HaloScan, SEMrush, Ahrefs) or your rank tracking tool

You will thus have a complete mapping of your site's URLs:

Top URLs (from a traffic / conversions / turnover perspective)
URLs that receive external authority
URLs in error or redirection
Etc.

Be sure to take all URLs into account - not just those of SEO interest - by looking at the overall traffic associated with each page.

This data will be useful later during the redirection plan, but also at the time of QA testing.

Also keep the data related to the title or meta description of each of your pages: these will be elements to verify later, to ensure that your SEO optimizations have been preserved after the migration.

Drafting SEO specifications

An SEO migration often occurs during a website redesign or a CMS change. This involves drafting clear SEO specifications intended for the developers who will work on the new version of your site:

Title and meta description templates for each page template
Hn tagging (H1, H2, H3, etc.) defined for each page template
URL format, trying to keep existing URLs as much as possible
Structured data to be implemented for each page type
Internal linking blocks
Content of the robots.txt file
Specifications for the XML sitemap
Etc.

Defining the redirection plan

The redirection plan is a must for SEO migration. Indeed, a migration is often accompanied by URL changes. The redirection plan then serves to link old URLs and new URLs, listing all the redirection rules to be implemented during the migration (generally, 301 redirections).

Implementing these redirections allows you to:

Indicate to search engines that your content has changed address, and that the new URL must now be taken into account
Transmit the acquired popularity signals from the old URL to the new one - especially if this old URL received backlinks
Direct your users to the correct page, thereby preventing them from landing on an error page

Take the list of your URLs obtained during the first step (crawl combined with other data sources), take the opportunity to do some cleanup if necessary, and map each old URL to its equivalent new URL to establish your redirection plan.

Testing on a QA environment

Before launching the migration, it is essential that you test in pre-production:

The new version of your site (post-migration)
The redirection plan

Testing the post-migration version

Run a complete crawl of the new version of your site on your QA environment. Check whether all your SEO specifications have been respected (title, meta description, URL, tagging, etc.), but also whether you detect other technical issues (4XX or 5XX errors, unoptimized elements, etc.).

Testing the redirection plan

Test your redirection plan in pre-production to ensure that:

Each source URL (URL to be redirected) returns a 301 response code
Each source URL redirects properly to the target URL you defined, and does so in a single step (no redirection chains)
The target URL (to which the user is redirected) matches the expected URL and returns a 200 response code

These tests should also allow you to check that there are no redirection loops.

Planning the migration

Is the new version of your site flawless from an SEO perspective? Is your redirection plan finalized and validated in QA? It is time to move to the production migration, in other words, the actual launch of this new version.

Beforehand, remember to take into account the latest content published on your site if necessary - if, for example, new content has been published between the time you prepared your redirection plan and its production launch. Care must also be taken to redirect the relevant URLs - only in the case of a URL change, of course.

Your redirection plan must therefore be implemented simultaneously with the live launch of your site migration.

If it is a domain name change, remember to validate the new Google Search Console property beforehand (and report the change of address there from the settings). This will allow you to retrieve as much data as possible as early as possible (clicks, impressions, but also indexing), and to submit your new XML sitemap.

Monitoring in production

Once the migration is effective, carry out another QA check of the site in production (complete crawl, testing of the redirection plan) to ensure everything is OK.

Further monitoring is then recommended:

Real-time monitoring of server logs at the time of migration, in particular to check URLs that return errors (4XX or 5XX)
Monitoring the redirection plan over the long term to verify that 301 redirections remain permanently in place on the site

How to track post-migration SEO performance?

After your migration goes live, you will then have to wait several days - or even several weeks - to get data on its impact, whether your goal is to maintain your SEO performance or to take advantage of the migration to improve your organic search results. Which indicators should you look at then?

Technical indicators

Crawl and indexing of your pages

Is Google crawling your new URLs properly? Have they been indexed? Analyzing your logs allows you to check the visits of Googlebot - Google's web crawler - to all your pages.

You can then track the indexing of your pages on Google Search Console. In particular, if you have submitted a sitemap file (or even several, segmenting them notably by page type), you can look more closely at the indexing of your pages:

What percentage of your pages has been indexed by Google?
Are there indexing discrepancies from one page type to another?
Which URLs are not indexed, and for what reasons?

Indexation in the Google Search Console

Web performance

If you have enough traffic on your site, the best way to evaluate the evolution of your web performance is to look at user data ("field data", as opposed to "lab data" which are only the result of simulations carried out under given conditions).

This field data represents the actual web performance data of users visiting your site. Google collects it through its Google Chrome browser and makes it accessible via the Chrome User Experience Report (Chrome UX Report).

The CrUX Vis tool, provided by Google, allows you to track the evolution of this user data with a weekly granularity, which is ideal for identifying trends.

Tracking the evolution of data in CrUX

Be sure to select the origin (rather than a specific URL) to see the evolution across your entire site (subdomain).

Traffic and business indicators

The indicators that will of course particularly interest you following your migration are those of organic traffic and those related to business:

Is your organic traffic growing compared to last year?
How is this organic traffic evolving by page type (for example, categories / product pages on an e-commerce site)?
Have your sales and conversions (and your turnover) increased?

Google Search Console will allow you to look at organic traffic data in more detail, and your analytics tool will allow you to closely track the evolution of sales or conversions.

Tracking traffic in Google Search Console

To make tracking easier, you can set up a report on Google Data Studio to track the evolution of organic traffic (with a comparison against the same period the previous year) for each page type, based on a Google Search Console data source. Depending on the nature of your site, you can segment your organic traffic to track changes on:

Product pages
Listing pages
Articles
Categories
The homepage
Etc.

Visibility indicators

The evolution of organic traffic is not always the most relevant indicator, since:

The click-through rate from Google's organic results has tended to drop over the years (the "zero-click search" trend, which has intensified with the arrival of Google AI Overviews, particularly on informational queries)
There may be a seasonality effect, and even when comparing to the same period the previous year, there may be stronger or weaker demand for your topic from one year to the next (for example, if you are a real estate agency, demand is strongly linked to the real estate market: changes in interest rates, legislative developments, etc.).

Consequently, the evolution of your visibility constitutes a more reliable indicator, since it is independent of the organic traffic actually sent by Google from its search results, but rather based on the evolution of your rankings: how has your positioning evolved on the keywords you target? Are you visible on more keywords?

If you use a rank tracking tool and have already defined a list of keywords that you monitor on a regular basis (daily or weekly), the evolution of this positioning gives you a good indication of whether or not your migration was successful from an SEO point of view.

Tracking migration on Monitorank

Otherwise, do not hesitate to set up rank tracking on a list of keywords relevant to your business before the migration.

Alternatively, you can rely on an SEO tool (such as HaloScan, SEMrush, Ahrefs, or Sistrix) that calculates a visibility index based on:

The keywords for which your site appears in Google search results
The position you occupy for these keywords
The assumed click-through rate (CTR) for that position and keyword type

Updating the visibility index of these tools can sometimes take several days to a few weeks, depending on the frequency of data updates. Note that a tool like SEObserver has data updated much more regularly, but on a more restricted number of keywords, allowing you to quickly see the evolution of your visibility.

Evolution of visibility on SEObserver

How to prepare and support your SEO migration with redirection.io

Thanks to all its features, redirection.io can support you through the different stages of your migration project, from the initial crawl to monitoring, including the definition and implementation of the redirection plan.

Analyzing the existing site with the crawler and real-time traffic logs

To prepare for your site's migration, the redirection.io technical SEO crawler allows you to identify all URLs attached to your site structure, and at the same time:

Errors
Internal redirections
The title, meta description, and tagging of each page
Etc.

Crawling a site with redirection.io

You can supplement and cross-reference this data with real-time traffic logs, in order to identify orphan pages, for instance, notably by filtering on the Googlebot user-agent (to see all URLs visited by Google's web crawler).

Filtering Google user-agent in redirection.io

Implementing your SEO specifications

Do you want to implement certain SEO optimizations, but your developers' bandwidth is limited for this within the scope of the migration or afterwards? redirection.io notably allows you to:

Optimize the title and meta description of your pages, either individually or in bulk thanks to the import feature
Create and modify your robots.txt file
Create and modify your XML sitemap file
Implement or modify canonical URLs
Add content to your pages: descriptive text, internal linking blocks, structured data, etc.

Optimizing titles with redirection.io

All these rules can be deployed autonomously from the redirection.io manager as soon as the tool is installed on your site. You are no longer dependent on IT or an external provider to implement your SEO optimizations.

Defining the redirection plan

With the redirection.io redirection generator, you can very easily automate the construction of your redirection plan. You simply need to enter the URL of your current site, the URL of the new version of your site (on your QA environment, for example), and then redirection.io - after crawling both websites - automatically maps the old and new URLs.

The redirection plan generator in action

The generated redirection plan can then be exported in CSV format, then imported into redirection.io (or any other tool of your choice).

Implementing the redirection plan

Have you defined your redirection plan? Deploy it in a few clicks thanks to redirection.io! You simply need to create your rules in the manager, or import them. Then, you can test it in pre-production using the "test mode", and make any necessary adjustments if needed, fully autonomously, without having to multiply back-and-forth exchanges with your IT team or web agency.

Testing all the rules in redirection.io

Once the migration is live, you just have to publish your rules for your redirection plan to be implemented in production.

Testing the redirection plan

To check the consistency of your redirection plan, you can test all your rules in a single click with redirection.io.

Once it is live, in QA and then in production, the redirection.io crawler allows you to launch a crawl on the list of URLs in your redirection plan to test them (response code, target URL, etc.).

A production crawl

Monitoring the SEO migration in production

Once your site is in production, the redirection.io log analysis feature allows you to monitor your SEO migration in real time: response codes, URLs crawled by Googlebot, etc.

Post-migration analysis with redirection.io

In the longer term, you can also ensure that your redirections remain properly in place over time in two ways:

By combining real-time traffic logs and notifications, so as to be alerted if one of your normally redirected URLs no longer returns a 301
By using the scheduled crawl feature to perform a regular crawl of the URLs in your redirection plan to ensure they return a 301

Validating the Google Search Console property

Does your migration involve a domain name change? Did your Google Search Console property validation drop during the redesign? You can handle this very easily from redirection.io. A ready-made recipe makes the task even easier for you.

Validating the Google Search Console property

What are the main errors to avoid during an SEO migration?

Not planning a redirection plan

Are your URLs changing? You must imperatively define and implement a redirection plan. Without this:

You will lose the keyword positioning acquired by your current URLs, and your organic traffic will drop
Google will not make the link between your old and new URLs
Your users risk landing on error pages
You risk losing the authority passed on by backlinks received by your site

Not testing in QA

You absolutely must test your site and your redirection plan in QA before launching your migration. Without this, you risk discovering post-migration SEO issues (unoptimized titles, error pages, orphan pages, etc.), with a potentially negative impact on your organic traffic, or finding yourself with a non-functional redirection plan, or with errors or redirection loops.

Using 302 redirections instead of 301

302 redirections are temporary redirections. If your URLs are changing permanently, then you must use 301 redirections, which allow popularity to be transmitted from old URLs to new ones.

Redirecting in bulk to the homepage

You should not try to redirect all your URLs at all costs. On one hand, there must be semantic consistency between the source URL and the target URL (you should only redirect to equivalent or closely related content pages). On the other hand, for pages with no SEO value (no organic traffic, no backlinks) that are not carried over after the migration, you can return a 404 or 410 error. Avoid bulk redirections to the homepage.

Launching a site in noindex or blocked from crawling

Sometimes, on certain QA environments, the site is configured such that:

The robots.txt file contains only a Disallow: / directive, which prohibits crawling of the entire site by robots
All pages have a noindex meta robots tag, which prevents their indexing

And, once the site goes live, these elements are sometimes left as is, meaning the site cannot be crawled or indexed, obviously resulting in a considerable impact on your visibility.

Not updating your internal linking

If your URLs have been modified, and your content has evolved (deletion, merging), you must take these modifications into account in your internal linking, so as to avoid having numerous broken links (which can harm the user experience) or internal 301 redirections: while this latter point is of course much less problematic, it is preferable to prioritize a direct link to the correct final URL (rather than going through one or more redirection steps).

Neglecting post-migration tracking

Once the migration is complete with the launch of the new version of the site, the implementation of the redirection plan (if necessary), and your SEO QA testing, your work does not stop there.

In the short and medium term, you must monitor site performance, whether technical indicators (page crawling and indexing by Google, web performance) or organic traffic (by segmenting by page type) to identify any anomalies
In the long term, your monitoring should allow you to avoid any regression (redirection plan, current SEO optimizations, etc.)

SEO migration checklist

This section presents a checklist of the different steps to follow to succeed in your SEO migration, from preparation to going live and post-migration tracking.

1. Scoping the project and SEO risks

Identify the type of migration (redesign, CMS change, site structure modification, domain change, content merging or deletion) and the associated SEO impact
Define SEO objectives: maintaining traffic, improving visibility, technical fixes, development of new pages
Identify critical pages: positions acquired, organic traffic, conversions, turnover, backlinks
Define the migration timeline

2. Analyzing the existing site

Run a complete crawl of the current site
Cross-reference and supplement with Google Search Console data, Analytics, XML sitemap URLs, URLs receiving backlinks, data from SEO visibility tools, etc., and aggregate the data for each URL
Export existing SEO optimizations (title and meta description of each page, etc.)
Identify existing errors to correct: 404, 500, orphan pages, etc.
Identify potential SEO optimization opportunities
Segment URLs by page type to facilitate the redirection plan, QA testing, and post-migration tracking

3. Defining SEO specifications

Define SEO specifications per page template: title, meta description, URL, h1..hn tagging, structured data, internal linking, etc.
Plan the content of the robots.txt file
Plan the content of the XML sitemap file

4. Building the redirection plan

List all old URLs (from the crawl and associated data) and prioritize them
Map each old URL to the equivalent new URL
Define the URLs requiring a 301 redirection (in case of a URL change), those for which to return a 404 or 410 response code, etc.
Finalize the redirection plan, taking into account the latest published content if necessary

5. Testing in a QA environment

Run a crawl of pre-production to perform a complete SEO QA check: response codes, title, meta description, URL, Hn tagging, structured data, internal linking, etc.
Test the redirection plan: source URL response code (301), expected target URL, target URL response code (200), absence of redirection chains or loops

6. Preparing and verifying the launch

Launch the new version of the site and the redirection plan live
Run a crawl of production to perform a complete SEO QA check
Test the redirection plan in production
If necessary, validate the new Google Search Console property, submit the XML sitemap file, and inform Google in case of a change of address

7. Monitoring after the migration

Monitor server logs: Googlebot crawls, URLs in error, etc.
Track page indexing in Google Search Console
Implement monitoring of the redirection plan to avoid any regression
Monitor the evolution of rankings on your keywords, your visibility, organic traffic, your conversions, and your turnover

Conclusion

By integrating SEO challenges as far upstream as possible into your migration project, you can make it a real growth opportunity for your visibility in Google search results.

At each step, redirection.io can support you, not only to save you time, but also to allow you to work on implementing the redirection plan and numerous SEO optimizations fully autonomously, without having to request help from your IT team, who are undoubtedly already busy with such a project.