Note: This guide was originally written in 2015, but it is updated every year to reflect relevant new trends and changes in the industry.

This guide is your website migration checklist; your map to ensure your migration has the lowest possible impact on your search rankings.

Website migrations typically lead site owners wanting to know any potential impact in advance. This is understandable because where SEO is concerned website migration projects rarely go to plan. Expectation management is essential both in anticipating the impact on your business and in developing a strategy to mitigate downtime.

In my experience each site is unique in its remit and comes with its own set of challenges, creating a need to approach each project with a strategy that aims to tick all the proverbial boxes. Our guide breaks into three key areas;

  • Site Migration Risks
  • Site Migration Types
  • Site Migration Checklist

Site Migration Risks

Take search rankings out of the equation and a site migration should be an exciting time for any company. The development of a new website or asset that aims to provide your customers with an improved browsing experience is one we frequently encourage, particularly if it provides a responsive solution. From an SEO perspective, however, a site migration can be very risky and potentially comes at the expense of lost traffic and revenue if not managed properly. Following are some the most common risks involved with the relaunch of the website.

Domain transfer 

One of the riskier forms of migration, a Domain Transfer sees ranking potential and rankings gradually transferred across to the new website as redirects are detected. We have found this process to take 4-12 weeks for full completion, depending upon the size of the site. 

Structural changes

A site’s hierarchy helps to dictate vertical and horizontal linking and should be considered to protect authority flow through the site. Failure to do so can result in lost rankings and poor communication with bots.

Doorway pages are but one consideration in this. A valuable approach can be to assess which pages on your existing site provide the most traffic and conversions, before ensuring they are given the same priority on your new site.

Content changes

If current content no longer exists or is radically changed to omit target keywords, rankings may decline.

It is prudent to ensure traffic providing content on your current site is given the same of improved exposure on your new site. Similarly, is it possible your existing site suffers from cannibalisation or doorway pages? Can you make similar pages more succinct by combining them into a single asset? Are there opportunities for improvement?  

URL restructuring (same domain)

A URL restructure can lead to both temporary and permanently lost rankings.

Temporary drops in ranking can be attributed to Search Engines recrawling and reindexing your site, and provided a robust redirect process is in place downtimes can be mitigated or reduced to 1-4 weeks (depending on the size of the site).

Permanent drops in ranking could occur if the URL structure is not as SEO friendly as your previous structure. This can include the addition of files, the removal of keywords, the lengthening of the overall URL, and a poor 301 redirect process.

Site Migration Types

There are a number of types of migration, each of which comes with its own considerations and requirements.

Existing Domain Migration

An existing domain migration is one in which your root domain remains the same. This often includes a redesign, CMS update, or URL/hierarchy restructure. Of the three types of migration available, an existing domain migration is one that should have the least impact on search performance (the expected migration time is 1-14 days depending upon site size) but can be dangerous if not carried out correctly.

Risks include technical changes, content alterations, URL restructuring, and hierarchy changes.

Time to migrate: 2-4 weeks

New Domain Migration

A new domain migration is one in which your domain changes. Perhaps you are moving to a new TLD (.com to .org), or combining a number of sites into a single asset? Either way, a new domain migration comes with the highest risk of any migration type, not least as the anticipated search impact could last up to 3 months, and must be handled with care.

This is due in part to the passing of link equity from your previous domain, as highlighted in the image below.

link equity flow with a new domain migration

Risks include an increased time to crawl and reindex the site, technical changes, content alterations, URL restructuring, and hierarchy changes.

Time to Migrate: 4-12 weeks

This is highlighted further in the following images which show Impressions data for a live client over the 90 day period after migration (domain size, circa-200 pages). visibility over time

The new version of the site witnessed a gradual increase in impressions, eventually matching the prior visibility of the old site 8 weeks after migration.

.org visibility iver time

The old site experienced a rapid decline in impressions immediately following the migration and still receives some visibility 90 days later. This created a period of around 6 weeks in which total domain visibility for the brand was reduced.

website migration visibility over 90 days

HTTP – HTTPS Migration

HTTPS migration is becoming a frequent culprit in reduced search rankings, not least as many proceed with the migration without fully knowing that it is one. A HTTPS migration is one in which your website remains the same, but has an SSL certificate applied to it. This in effect completely changes every URL on your website from one that begins with HTTP to HTTPS. The difference is subtle, but the impact is significant.

Google has stated that making the switch to HTTPS can positively influence your search rankings, giving enough motivation to many webmasters to make to switch. At the core of this transition however is a complete URL restructure, and is one that can have a significant impact on rankings (as discovered by Moz).

Update: considerations for HTTP-HTTPS migrations in 2018, including;

  • migrations appear to be occurring much quicker recently, in comparison to the timings initially observed in 2015, with one particular example being remapped within a few days. The time for a complete migration will still vary based on the size of the domain, available crawl budget, etc.
  • as more websites commit to HTTPS protocol the more Google are able to give it weight as a ranking metric. Last year, Google’s Gary Illyes stated that 34% of Google’s indexed are HTTPS, allowing them to dial up the algo. This could provide additional motivation for webmasters to make the switch to HTTPS.
  • Google’s John Mueller gives tips on how to successfully migrate a site from HTTP to HTTPS.

Risks include URL restructuring – Time to Migrate, 1-2 weeks.


Combining Domains

Combining domains represents the process of compounding your assets to a single location. This may include the migration of multiple domains to a completely new one, or the migration of smaller domains to your main website. As previously discussed, porting to a new domain will result in a longer migration, and appropriate considerations towards the impact on your business should be taken. You may also want to reconsider migrating some websites. Google has been prolific with Webspam Penalties over the past few years, and caution must be taken if redirecting a site with a poor backlink profile.

Benefits include a combining of Domain Authority which could lead to improved rankings. Risks could involve penalties if combining domains with a poor link profile.

Time to migrate: 2-4 weeks

Site Migration Checklist

  • Rank Monitoring
  • Technical & Content Audit
  • Redirect file
  • GA Audit
  • Offsite Asset Audit
  • Sitemap Management

Rank Monitoring

Rank monitoring is an essential initial step in the website migration process as it allows visibility on loss and gain of search exposure. It is very likely that there are many hundreds of keywords that provide your site with traffic every month, and whilst monitoring all of them is not essential, tracking top-performing or high volume keywords can provide confidence that your campaign is moving in the right direction.

I would advise monitoring keyword rankings for a number of weeks prior to migration. This provides insight on ranking trends and fluctuations, allowing you to establish which keywords are consistent contributors to your site’s exposure. It would be an idea to set these as priority keywords to provide quick access to their performance.

You should be monitoring a number of metrics;

  • Keyword
  • Ranking position
  • Ranking URL[s]

By monitoring keywords in this way you are able to assess which keywords have been positively or negatively affected by your migration, providing insight on where opportunities for optimisation may lie. Ultimately, monitoring your keyword rankings affords confidence that your migration has either been a success or where it needs remediation.

Selecting Keywords to track

We typically utilise a number of tools to pull data on suitable keywords, including Google Analytics and Webmaster Tools (now Search Console). You may also wish to use the Adwords Keyword Planner for more inspiration on finding relevant keywords, combining all potential keywords before entering them into your Rank Tracking software.

Tracking Tools

You will likely need to subscribe to a suitable tool to assist you in monitoring rankings. There are a number of options you may consider. CandidSky uses their proprietary RankTracker, but good options include AWR (Advanced Web Rankings), and SEO Powersuites Rank Tracker, both of which come with instructions on how to manage your campaign.

Technical & Content Audit

The best migration procedure in the world is fruitless if the site being migrated too is of a lesser technical quality than your existing asset. To allow for better attribution in Correlation vs Causation we must also assess technical and content components that may contribute to a decrease in rankings.

Before launching your new site it is advisable to host your new assets on a test server to provide analysis and information on potential pitfalls.

**Top Tip** When hosting a test site ensure you have a password set on your test domain and robots set to “noindex” to prevent search engines from indexing your content prior to launch.

Site speed

Google may never have alluded to a sites load speed having an effect on its search rankings. The evidence that this metric contributes to a sites Organic visibility is, however, overwhelming to the point where Google do provide developer tools to assist Webmasters in identifying page load speed opportunities.

Though not technically a necessary part of a migration, migrating to a site that is significantly slower than your current asset could contribute to limitations in recovery.

  • Test your current sites page load speed (Pre-Launch)
  • Test your new sites page load speed on a test server (Pre-Launch)
  • Ensure your new site is quicker to load than its predecessor-to-be (Pre-Launch)
  • Test your new sites page load speed (Post Launch)
  • Ideally, your page load speed should be less than 5 seconds, with 2 being a good target

Site Hierarchy

Hierarchy is seemingly becoming a more significant contributing factor in recent years, particularly as cannibalisation is increasing in line with Google’s ever-growing index.

Crucially, hierarchy communicates the priority and importance of landing pages in line with potential counterparts, and dictates which should rank higher in search. This can be communicated with bots in a number of ways, from navigation linking (vertical) to your internal link structure (horizontal).

Hierarchy Considerations

  • Does your navigation allow access to top service pages or product categories?
  • Does cannibalisation occur within your hierarchy?
  • Are product pages available with a maximum of 3 clicks?
  • Is your internal linking strategy designed to allow authority flow?

Duplicate content management

Duplicate content is a major factor in search visibility. So much so that it warranted a post of its own. Read the full article here.

Content Management

Where your website currently ranks is based on a number of metrics, from Domain Authority (the management of which is considered in our redirect process), through to page-level data like content, page titles, headers, alt tags, etc. If anything, it’s quite likely that this is the area where you will see some problems with your SEO site migration. 

We aren’t looking to optimise your website to rank better at this stage. Migration should be considered a damage limitation, and it is likely you may want to come back post-launch and further optimise your content to rank better for desired keywords. But for now, the aim will be to ensure your high ranking pages stay up there! Some things you might want to consider include:

  • The migration of comments (particularly if they add value to the original piece).
  • Page titles, and header tags (H1’s, H2’s, etc)
  • Internal links should be updated to their new location (see the following Broken Links section for more info).

Broken links

We have already spoken about the importance of internal linking in communicating hierarchy… it is indeed surprising that in the excitement of launching a new site so many Webmasters neglect to update the URLs their links point to.

The situation? A user visits your site and clicks a contextual (in content) link to a page you have told them will aid them.

The issue? The link still points to the old page, leading them to a 404 error, and probably a small cup of frustration.

The solution? Many assume the best solution would be reliance on 301 redirects. This would, after all, redirect a user to the desired content. The drawback with this solution is the lost link authority through the redirect. The best solution is a database look up to change all contextual links to their new location.

The process? This actually has considerations for both pre and post-launch. Pre-launch it would be beneficial to use the redirects file (discussed below) to identify donor and redirect pages, using a database lookup function to update all together. The pre-launch redirect procedure will never get every URL, so this process should also be followed post-launch with any freshly identified 404 errors.

Redirect file

The redirect process is possibly the most crucial element of a site migration. It’s effectively responsible for ensuring search engines know where your content has moved to.

Redirects are crucial in:

  • Ensuring link equity is passed to the new site/page
  • Ensuring Bots understand the nature of the redirect (permanent vs temporary)
  • Allowing for deeper crawling of a site following launch.

There are three types of redirect we consider when migrating a domain;

Page to page redirects

Page to page redirects are vital if your site pulls traffic from a diverse collection of URLs. This may include redirecting product pages to their counterpart on the new site, category pages to their new location, and informational content to the most appropriate page. Considerations for this must also include links to each page to ensure anchors are managed and potential cannibalisation contained.

Page to parent redirects

The launch of a new site can offer an opportunity to clean up your product offering. With this, you might opt to redirect expired products or even those that do not pull traffic, to a parent or category page. In addition to decreasing the number of pages involved in your recrawl, this approach can also manage authority flow to pages with better ranking potential.

Page to root redirects

A page to root redirect is when all pages of a site are redirected to a single location, usually the root, or homepage. There are instances where the benefits of page to page redirects are inefficient enough that a page to root redirect is the most practical solution. This can include when aiming to pass domain authority when combining a site.

Our very thorough page to page redirect process

  • Pull a full list of available URLs for your existing site with a crawl agent. Our preference is with Screaming Frog, but there are plenty of others including Xenu, Integrity, and Website Auditor.
  • Import this data into Excel and use some wizardry to remove URLs with parameters, and duplicates.
  • Run this list through a HTTP response checker (such as, or scrapebox) to provide a complete list of status codes. Move any 404 pages to a new tab, keeping any 301 and 200 status pages.
  • Now run a crawl on the test server to source a list of the new site’s URL structure, before using a VLOOKUP function to identify which URLs are changing, and which are remaining the same.
  • Take your list of expiring/donor URLs (those which will have a new file path) and manually map their new location on the new site (you may be able to use footprints to automate some).
  • We now have a complete list of expiring URLs and their new location. The next step will be determining which of the already expired pages (those with a 404 status code) have value, and should be redirected.
  • Take your 404 pages and run them through a link-monitoring tool (options include aHrefs, Majestic, and OSE – it’s advisable to use them all to ensure thoroughness). This will provide insight on which 404 pages should be redirected to a suitable page. Any 404 pages that have no inbound links can be discarded.
  • Import the suitable 404 pages into your redirect list, and add a suitable redirect to a page that would benefit from the link equity and anchor.
  • With your donor URLs and redirect URLs complete using the concatenate function in Excel to generate the required redirect code for your server.

GA audit

An often-overlooked element is the migration/updating of Google Analytics data, which ultimately limits your ability to effectively track site usage through the migration. A complete GA Audit will be covered in a future topic, but below we’ve shared the main considerations for a migration:

Update: Talking about migrations, have you made the switch to GA4? Here’s why you should:

  • Flexibility and accuracy when tracking user behavior
  • Much more data feedback and insights
  • Ability to track users across devices and platforms
  • Universal Analytics will discontinue in July 2023, so now is a better time than ever!

**Top Tip** I tend to advise updating the name on the existing GA account as opposed to creating a new one to work with, as this allows for direct comparisons over time.

Considerations include

  • Updating of Goals
  • Updating of Ecommerce
  • Ensure tracking codes are on the new site
  • It is also beneficial to create a property set in Search Console to assist in monitoring the exposure of combined sites through the migration period and beyond. Learn more here.

Offsite asset audit

There are two elements to an offsite asset audit. These centre around either assets for which you have direct control, or assets owned by third-parties. An audit of each of these areas can ensure your inbound link equity remains as high as possible.

Owned assets

You most probably own a number of offsite assets, potentially including Google My Business pages, Facebook pages, Twitter Accounts and more. These are pages you can log in to yourself and update for data congruency. Where possible it is advisable to update any owned assets with the details of your new domain to ensure any authority from them passes straight over, and not through a redirect. Please find a list of relevant redirect tutorials below;

Third party assets

There are also most likely a ton of third-party assets linking to your domain. Whilst you could certainly use a link tracking tool such as Ahrefs, Majestic, or Moz/OSE to find links, it may not be practical or possible to locate and contact the owner to request updates on all of these (though you would be awarded with more link equity if you chose to do so).

But we do advise updating of any directory listings you may have submitted data to. As Google aims to collate information across citations, data congruency is an important element for local SEO, and having different domains listed across profiles could lead to inconsistencies and a loss of trust. Update any existing profiles as opposed to creating new ones.

Sitemap management

What’s mostly responsible for a delay in updated search rankings? It’s the rate that search engines crawl and reindex your site. To make it easier for them, upload multiple sitemaps to your domain so they have access to as many URLs as possible!

Recommended sitemaps;

  • Expired URL sitemap (providing access to removed URLs to promote the crawling of redirects)
  • New URL Sitemap (providing access to new URLs to promote the crawling of the new hierarchy)

Sitemap procedure

  • Ensure both maps are accessible on the migrated site
  • Submit both to GWT
  • Fetch the URL of each within GWT, requesting ‘All’ linked pages are crawled.


It’s far from being a simple task (trust us, we know!). But an SEO site migration managed correctly can result in a massive lift in search exposure. By following the pre- and post-launch procedures you can shield your website from the potential negative impacts of migration; paving the way to a stronger future for your website and business.

Want some further information on website migrations or would like to hire us for a migration project? Please either comment below or contact our SEO consultants.

Pre-launch process

  • Set up rank monitoring
  • Assess the new site for content and technical compliance
  • Prepare a 301 redirect file
  • Take a copy of your sites existing sitemap

Post-launch process

  • Immediately following launch run a Site:Search to pull a complete list of all indexed URLs. Run these URLs through a HTTP response checker and clean up any missing or incorrect redirects.
  • Use GWT to determine any missed redirects and add to the original redirect file using the process above.
  • Update Google Analytics Tracking/Goals etc
  • Request a crawl of your old sitemap
  • Request a crawl of your new sitemap
  • Confirm site migration in GWT (external domain migration only)
  • Create GWT property set to allow assessment of combined asset visibility
  • Update offsite assets

For more details on our approach to website migration, or to share any questions or feedback, please contact us on our social channels, or at Want to find out what makes us one of the best SEO companies in Manchester? Take a look at our case studies to see the amazing results we’ve achieved for our clients.