Baseline
The list of URLs that bring traffic, have external links, or convert – from Search Console, analytics, a crawl, and link data. Without it, there’s nothing to compare after launch.
SEO migrationSite migration
Site migration
without losing traffic.
A new platform, a new domain, or a new URL structure is when organic traffic is easiest to lose – and hardest to win back. Before you switch, I record what brings traffic today, build the redirect map, and check the new version URL by URL. After launch, I measure whether everything carried over.
In short
What is an SEO migration?
An SEO migration is the planning and control of any change that affects how search engines see a site: a new domain, platform, URL structure, templates, or language versions. The goal is to carry traffic, links, and rankings over to the new version – through a redirect map, pre-launch checks, and post-launch measurement.
When it’s worth doing
- You’re changing your CMS or ecommerce platform
- You’re merging several domains into one, or changing domain
- You’re rebuilding the URL structure or navigation
- You’re adding or removing language versions
- The migration already happened and traffic dropped
When it’s not enough
If the old site has serious technical problems or hundreds of pages it doesn’t need, a migration is a good moment to fix them – pair it with an SEO audit or a content audit instead of moving the problems to a new platform.
Scope
What a migration covers
Six elements that decide whether traffic carries over. Each ends with a test you can run before and after launch.
Redirect map
A 301 from every old URL to its closest equivalent, with no chains and no blanket redirects to the homepage.
Pre-launch comparison
A crawl of staging compared with production URL by URL: titles, headings, canonicals, hreflang, structured data, noindex, internal links.
Rendering and performance
Whether content is visible without JavaScript, whether new templates hurt Core Web Vitals, and whether AI bots get the same content as Google.
Launch day
A checklist: redirects work, robots.txt doesn’t block the site, the new sitemap is submitted in Search Console, the Change of Address tool is used for a domain move, analytics is collecting data, and the launch is annotated.
Post-launch review
Traffic, indexing, and errors compared with the baseline at 2 and 4 weeks, with the URLs that lost the most and a cause for each. For large migrations, monitoring runs for 60–90 days.
How I work
From baseline to post-launch review
- 01
Plan and risks
We agree what’s changing, when it launches, and who implements. I point out the biggest traffic risks before the team starts building.
- 02
Baseline
I record the pre-migration state: URLs with traffic, links, and conversions; rankings; indexing; performance.
- 03
Map and spec
The redirect map and SEO requirements for the new templates – as developer tasks, each with an acceptance criterion.
- 04
Pre-launch check
A crawl of staging, a comparison with production, and a redirect test on the full list. Launch only after blockers are closed.
- 05
Launch and review
A launch-day checklist, measurement at 2 and 4 weeks, fixes where traffic didn’t carry over, and monitoring for 60–90 days.
Post-launch review
What a good migration looks like in the data
Weekly clicks from Search Console against the pre-migration baseline. A short dip after the switch is normal – Google has to process the redirects.
The checks at 2 and 4 weeks tell a swing from a loss. If the curve doesn’t come back, I look for the cause URL by URL.
- Clicks
- Baseline
Redirects from the map working
100%
404s with traffic
−92%
Illustrative example – a shape typical of a well-run migration, not a specific client’s data.
What you get
A map that passes its test before launch
The redirect map is a sheet where every row has the old URL, the new URL, the reason for the choice, and the test result. Plus a developer spec and a post-launch report.
A category URL after a platform change
- Old URL
- /category/womens-shoes?page=1
- Value
- Traffic from a few dozen queries, links from several domains
- Staging
- Redirects to the top-level category, not the equivalent
- Fix
- 301 to /women/shoes, page parameter dropped from the canonical URL
- Sign-off
- The old URL returns a single 301 to /women/shoes; the target returns 200 and is indexable
Illustrative example – it shows the format, not a specific client’s data.
Honestly
What to expect
Redirects fully testable
Every URL in the map can be tested before and after launch. There’s no room for “probably works.”
Traffic swings normal
For a few weeks after a big migration, rankings can fluctuate while Google processes the changes. The post-launch review tells a swing from a loss.
Launch decisions out of my control
If the launch date doesn’t leave time to close blockers, I say plainly how much traffic is at risk. Whether to launch stays your call.
The cheapest moment to bring SEO into a migration is the start of the project. The most expensive is a week after launch.
Pricing
What drives the cost
Every migration is different, so there’s no fixed price. Four things affect the quote:
Number of URLs and templates
A company site with a hundred pages is a different scale from a store with tens of thousands of products and filters.
Type of change
A CMS change with the same URLs is simpler than a domain and structure change at once.
Languages
Each language is its own map, its own hreflang, and its own post-launch review.
When I join
From the start of the project, just before launch, or after it – in the last case, I start by finding the losses.
After a short call, I send a proposal with scope, timeline, and price – before any work starts.
Related services
SEO
SEO audit
Technical health, content, links, and AI readiness – findings grouped by root cause, prioritized by business value, each with an acceptance criterion.
MoreGEO · AEOAI search visibility
So ChatGPT, Perplexity, Gemini, and AI Overviews can find, understand, and cite you – measured, not promised.
MoreContentContent audit
A decision for every URL: keep, update, merge, or remove – with cannibalization, decay, and a redirect map.
MoreFrequently asked questions
Does a site migration always lose traffic?
Not always, but the risk is real, especially when URLs change. Short ranking swings after a big change are normal. Lasting losses usually come from missing redirects, changed content, or blocked indexing – and those can be caught before launch.
When should SEO join a migration project?
At the start, when the URL structure and templates are being designed. Then SEO requirements are ordinary backlog tasks. Just before launch, all that’s left is checking and a list of blockers.
Should every old URL be redirected?
Every URL that has traffic, external links, or internal links – to its closest equivalent. URLs with no value and no equivalent can return 404 or 410. Google usually treats blanket redirects to the homepage like a 404.
How long until traffic recovers after a migration?
Google says it can take a few weeks or more for new URLs to replace old ones in results, with ranking fluctuations along the way. That’s why I review at 2 and 4 weeks and, for large migrations, monitor traffic for 60–90 days. Redirects stay in place for at least a year, as Google recommends.
How long does an SEO migration take?
It depends on scale. The baseline and redirect map take from a few days for a site with hundreds of URLs to several weeks for tens of thousands. The staging check usually takes a few days, plus time to fix blockers. After launch comes monitoring for 60–90 days. We set dates at the start, in line with the development team’s schedule.
Why hire an SEO specialist instead of the dev team or the agency building the site?
Developers are responsible for making the new site work. A redirect map based on traffic and links, a URL-by-URL comparison of staging and production, and post-launch checks are separate work that build projects rarely have time for. I work with your team, not instead of it.
When should a page return 404, and when 410?
Both codes say the page is gone. A 410 says it was removed on purpose, so search engines can stop visiting it sooner. I use 410 for URLs with no value and no equivalent, and leave 404 for accidental errors. Any URL with traffic or links always gets a 301.
The migration already happened and traffic dropped. What now?
I compare the pre-migration state – from Search Console and archived data – with today and find the URLs that lost the most. The usual causes are missing or wrong redirects, lost content, and indexing problems.
Do you implement the redirects yourself?
Implementation stays with your developers. I prepare the map and spec, test staging, and check production after launch.
Let’s plan the migration
before you switch.
Tell me what’s changing and when you plan to launch. I reply within one business day.
Ask about a migration