Website migration checklist: protect your SEO before, during and after

A website migration checklist is the ordered list of tasks that move a site to a new design, platform, structure or domain without losing the search traffic and links it has earned. The core of it is simple: record benchmarks, map every old address to its new one, set permanent redirects, test everything on a staging copy, launch at a quiet time, then watch search and analytics closely for at least 30 days. This guide sets out the checklist in three phases, explains the redirect map in detail and covers multilingual sites, where most migrations lose the most.

Last updated: 24 October 2026.

What counts as a website migration?

A migration is any change that alters the addresses, content or technical base that search engines know. The common types are:

• Redesign with new structure: pages are merged, renamed or moved.
• Platform change: for example from one CMS or shop system to another.
• Domain change: a new name, or several country domains merged into one.
• Protocol or host change: HTTP to HTTPS, or a move to a new server or subdomain.
• Language change: adding languages, or moving them into folders or separate domains.

Each type carries its own risk, and many projects combine several at once. The more you change in one go, the harder it is to find the cause if traffic drops.

At Odduel, a creative and technology agency in Barcelona and São Paulo, migrations are part of our website redesign service. We plan the redirect map before the design is approved, not the week before launch.

In short: benchmark traffic, rankings and links; crawl the old site; map every old address to the closest new one; set permanent (301) redirects; test on staging; launch with the redirects live from the first minute; submit the new sitemap; then check redirects, errors, indexing and traffic daily for two weeks and weekly for a month.

The website migration checklist at a glance

Phase	Tasks	Owner
Before	Scope, benchmarks, crawl, valuable pages, redirect map, content kept, technical basics, staging tests	Project lead, SEO, developers
Launch day	Redirects live, blocks removed, key tests, sitemap, change of address, analytics, external links	Developers, SEO, marketing
First 30 days	Daily then weekly checks of errors, redirects, indexing, traffic and conversions; fast fixes	SEO, developers

What should you do before the migration?

Most of the work, and most of the protection, happens before launch.

1. Write down what is changing and why. Domain, structure, platform, design, content, languages. Decide whether some changes can wait for a second phase.
2. Record benchmarks. Organic sessions and conversions by page over the past year, top queries and pages in Search Console, indexed page count, backlinks to the site and their target pages, and page speed on key templates.
3. Crawl the old site. List every address that returns content, including PDFs, images that receive traffic, old campaign pages and every language version.
4. List your most valuable pages. The pages that bring most traffic, conversions and links. They get the most care in the map.
5. Build the redirect map. One row per old address, with the new address it should go to (see the next section).
6. Keep what ranks. Where a page ranks well, keep its topic, main headings and depth on the new page, even if the design changes.
7. Prepare the new site’s technical basics. Titles and descriptions, canonical tags, hreflang for languages, structured data, an XML sitemap, a correct robots file and analytics.
8. Test on staging. Crawl the staging site, test a sample of redirects, compare titles and headings with the old pages, and keep staging closed to search engines.

How do you build the redirect map?

The redirect map is the single most important document of a migration. Search engines follow permanent redirects and pass most of the value of the old page to the new one, as Google explains in its guidance on site moves with URL changes.

Old page	Situation	What to do
Same content, new address	Page moved	301 to the new address
Two old pages, one new page	Content merged	301 both to the merged page
Page removed, close equivalent exists	Content replaced	301 to the closest equivalent
Page removed, nothing equivalent	Genuinely gone	Return 410 or 404; do not send everything to the home page
Language versions	Each language moves	301 each to its own new language page
Files and images with traffic or links	Moved	301 to the new file address

Avoid chains (one redirect leading to another), loops and mass redirects to the home page, which search engines tend to treat as missing pages. Keep the redirects in place for at least a year, and in practice for as long as the old addresses receive visits or links.

What happens on launch day?

1. Launch at a quiet time for your business, with the team available.
2. Switch redirects on at the same moment the new site goes live.
3. Remove any staging blocks: robots rules, password protection and noindex tags.
4. Test redirects for the most valuable pages and a random sample of others.
5. Check key journeys: forms, checkout, sign-in, search.
6. Submit the new XML sitemap in Search Console, and use the change of address tool if the domain changed.
7. Check analytics and consent are recording on the new site.
8. Update the links you control: social profiles, business listings, email signatures and advertising.

What should you check in the first 30 days after launch?

Some problems only appear when search engines recrawl the site, which takes time. Watch closely.

1. Daily for two weeks: crawl errors and 404s, redirect behaviour, server errors, indexing in Search Console, organic traffic to the most valuable pages.
2. Weekly for a month: rankings for top queries, conversions from organic search, backlinks pointing to old addresses, page speed.
3. Fix fast: add missing redirects as 404s appear, correct titles and canonicals, restore content that was cut from pages that lost rankings.

A temporary dip is common while search engines process the change. A drop that grows after the second week usually points to missing redirects, lost content or a technical block.

How do you migrate an online store?

Shops add their own risks. Product and category addresses usually change between platforms, and they carry most of the search traffic, so map every product, category and filter page that receives visits. Move customer accounts, order history and addresses with care for data protection, and tell customers if they need to reset passwords. Keep product identifiers, reviews and structured data so rich results survive. Place real test orders on every payment and delivery method before launch, and watch failed payments and abandoned checkouts closely in the first weeks.

How do you migrate multilingual and multi-domain sites?

Migrations of sites in several languages lose the most when language versions are treated as one site. Keep these points on the checklist.

• Map every language version separately, including translated addresses.
• Update hreflang so each page lists its new equivalents in every language, and nothing points to an old address.
• When merging country domains into one, redirect each country domain’s pages to the matching language folder, not to the home page.
• Check that translated titles, descriptions and structured data moved with the pages.

Who should run the migration?

A migration touches design, development, content and search at once, so it needs one person accountable for the whole checklist, usually the project lead, with an SEO specialist owning the benchmarks and the redirect map and developers owning the redirects, the technical basics and the staging tests. Content owners must confirm that nothing important was cut. Whether that team is in-house or external, the roles are the same; our comparison of a website redesign by an agency or in-house helps decide who covers which part.

What are the common migration mistakes?

• Planning redirects in the last week, after the structure is fixed.
• Launching with the staging block still in place.
• Redirecting everything to the home page.
• Cutting the content of pages that ranked well because it did not fit the new design.
• Changing domain, platform, structure and content all at once without a reason.
• Stopping the checks after launch day.

Our website redesign process explains where the migration fits in the wider project, and our comparison of Webflow vs WordPress helps if the migration includes a platform change.

Questions people ask

Start your redirect map today: crawl the current site and list its most valuable pages. If you are planning a redesign or a move and want it done without losing what the site has earned, see our website redesign service or tell us about the project.