Another honest comparison guide? I bet that is exactly the question you have in your mind right now. And honestly, it is okay to be skeptical about reading another “best SEO website migration agency” article that was clearly written to promote someone's services.
We completely understand the frustration, especially when all you want to do is migrate your website without losing your SEO and get back to running your business.
That is exactly why we put this guide together. But we will say this upfront: yes, we offer website migration SEO services, but no, we are not on the top 6 list.
Why? You ask.
Not because we are not good at what we do. It is simply because this is an honest guide. So, we will compare the top six website migration agencies that handle complex migrations without destroying the SEO you have spent months or years building. We picked these agencies based on their past results, technical SEO expertise, post-migration support, and the work they have publicly documented, so you know exactly what to expect.
A Quick Note Before We Start
Website migration is one of the highest-risk SEO projects a business can go through. Get it right, and your traffic survives the move, maybe even grows. Get it wrong, and you can lose 30 to 90 percent of your organic traffic almost overnight, and recovery can take well over a year.
The agencies below have all published real website migration case studies. That is the bar we held them to.
Top 6 agencies offering website migration services without losing SEO
The best 6 agencies offering website migration services in 2026 are Polaris Agency, Hallam, Elixirr Digital, Delante, Found, and Edge45.
| Agency | Best for | Post-migration Support | Technical SEO Depth |
| Polaris Agency | E-commerce, enterprise, international, and M&A migrations | Yes | Deep (5-stage framework, recovery projects) |
| Hallam | B2B brands, WordPress migrations, redesigns | Yes | Strong across UX, dev, and SEO |
| Elixirr Digital | International SEO rollouts, CMS replatforms | Yes | Strong (SEO-led redesign and structure work) |
| Delante | International, multilingual, and e-commerce migrations | Yes (ongoing SEO included post-migration) | Strong (own indexing tool, 2,000+ websites optimized) |
| Found | Rebranding, multi-domain, TLD migrations | Yes | Strong (15+ years, AI and traditional search coverage) |
| Edge45 | B2B, niche e-commerce, technical SEO audits, recovery | Yes | Strong (6-phase migration framework) |
None of these agencies publishes fixed pricing, which is common for complex SEO migration work. Scope, site size, and number of URLs all affect cost. Reach out to each for a quote based on your specific project.
1. Polaris Agency
Polaris is a London-based SEO agency that has been operating since 2009. Website migrations are not a side service for them; they are a core specialty with their own dedicated section on the website, multiple published case studies, and sub-services that cover everything from e-commerce migrations to international and WordPress-specific moves.
Their migration approach runs on a 5-stage framework: benchmarking existing performance, planning, pre-launch testing, monitoring indexation and keyword visibility post-launch, and ongoing refinement.
Published case study
E-commerce gifting retailer migration recovery
This project involved recovering 48% of lost performance for a promotional merchandise retailer after a failed migration. The client came to Polaris after the damage had already been done, which shows they handle recovery work as well as proactive migration planning.
They also completed a full migration for Detecon, a European enterprise with a bilingual site, a complete rebrand, and a Drupal-to-WordPress replatform happening simultaneously. That project resulted in a 133% increase in daily site visits post-migration.
Unique perks
They publish some of the most detailed migration case studies available from any UK agency, including M&A brand splits, agricultural rebrands, and multi-domain consolidations. Their migration recovery service is specifically designed for businesses that have already suffered a traffic hit from a botched migration. They also offer a migration performance recovery track for brands that did not use an agency during the original move.
2. Hallam
Hallam is a multi-award-winning B2B digital marketing agency with offices in Nottingham and London. Website migration is part of their broader SEO and web development offering, and what makes them stand out is the cross-team collaboration they bring to a migration project.
When you work with Hallam on a migration, you get a dedicated SEO consultant who audits your existing organic performance, including rankings, backlinks, and traffic, alongside a dedicated account manager and project manager.
After launch, their specialist team monitors organic performance to make sure it maintains or improves from launch day. They also include a hypercare period where the team picks up and resolves any issues or bugs that surface post-migration.
Published case study
tvONE website migration to WordPress
Hallam handled a full website redesign and WordPress migration services for tvONE, resulting in an 83% increase in events. This case is notable because it shows their ability to improve on the migration, not just maintain performance.
Unique perks
Their migration work is backed by UX, web development, and digital PR teams working alongside the SEO team, not in isolation. As WordPress specialists, they are a particularly strong fit for brands migrating to or within the WordPress ecosystem.
3. Elixirr Digital
Elixirr Digital is the digital arm of Elixirr, a publicly listed global consultancy. Their comprehensive SEO website migration services cover all aspects of the migration process, from pre-migration planning to post-migration monitoring, and they handle domain migrations, HTTP to HTTPS transitions, CMS changes, and more.
What sets them apart is how they approach migrations with an international growth lens. They are not just moving a website; they are often simultaneously expanding into new markets while protecting existing traffic.
Published case study
B2B events agency, SEO-led website migration
Elixirr Digital worked with a global B2B events and experiential agency on a project that combined SEO, UX improvements, and a carefully managed site migration. The result was organic search accounting for 45% of the agency's total traffic, driven by steady MQL growth throughout the engagement.
Unique perks
Strong track record in international and multi-market migrations where domain structure and hreflang implementation need to be precise. They have a published case study of a Sitecore-to-WordPress replatform for a corporate financial services firm that generated €20m in pipeline post-migration.
4. Delante
Delante is a Krakow-based international SEO agency founded in 2014. They have optimized over 2,000 websites and operate across 32+ countries in over 40 industries. They are well-regarded for their transparency, their focus on business outcomes over rankings for the sake of rankings, and their hands-on approach to implementation.
Their SEO migration process starts with precise planning, including choosing the right timing for the migration, specifying URL structures if they are changing, and working through every phase systematically from backup to post-launch monitoring.
One thing Delante does differently is that they do not hand off a list of recommendations and walk away. They implement the work themselves, which matters during a migration when timing and sequence are everything.
Published case study
Aesthetic medicine website migration recovery
Delante published a case study on how they rebuilt visibility and traffic after a website migration for a client in the aesthetic medicine industry, restoring overall visibility to three times what it was before the drop. The client had experienced a sudden and significant visibility loss, and Delante worked backward from the damage to identify and fix what went wrong.
Unique perks
Their dedicated SEO specialist model means you have one consistent point of contact throughout the migration, not a rotating team.
5. Found
Found is a London-based digital agency with over 15 years of SEO experience. They manage the full migration process from start to finish, covering both technical and SEO requirements, and their portfolio includes projects that preserve both traditional search and AI platform performance.
They work across domain migrations, CMS transitions, redesigns, and HTTPS migrations. Their approach is collaborative, with SEO embedded across all channel considerations, not treated as an afterthought.
Published case study
The Clermont Hotel Group rebrand migration
This is one of the more complex migration scenarios you will find documented anywhere. The Amba hotel brand was being retired and replaced with The Clermont brand. Found was responsible for migrating four hotels across two domains, one new and one existing, while retaining the branded search demand from users still searching Amba terms.
The project happened during the UK Covid lockdown, which made benchmarking traffic performance nearly impossible. Found pivoted their success metrics to keyword rankings and competitive positioning. When the hotel market reopened, they had outranked key competitors across 50+ high-priority terms and retained number-one positions for the original branded terms.
Unique perks
Strong track record in hospitality, travel, and high-brand-sensitivity migrations where the rebrand and the migration must happen simultaneously without losing demand.
6. Edge45
Edge45 is a York-based SEO agency with a strong technical reputation and a migration methodology they describe as refined to an exact science. Their 6-phase website migration framework covers comprehensive planning, staging website creation, pre and post-launch SEO audits, and includes checking for broken pages, redirects, missing meta tags, and proper installation of analytics tools.
What makes Edge45 worth considering is that they put their methodology on the line publicly. They have done their own agency site migration and documented every result, which is about as honest a proof of capability as you can get.
Published case study
Netsells Group
Netsells, a leading software development agency ranked the 9th fastest-growing tech company in the north of England, hired Edge45 to handle their own website migration after having worked with them on multiple client migrations first. The fact that a web development company that clearly understands the risks chose to bring in Edge45 as a specialist is a strong signal.
Edge45 also handled the migration for I-Finity Associates, a York-based software agency, which then saw a 275% increase in leads year-on-year post-migration.
Unique perks
They handle recovery projects for businesses that have already suffered ranking drops from a poorly executed migration and have reversed traffic slides back to record organic levels for clients. Strong peer validation: web development agencies that understand SEO website migration risks have repeatedly chosen Edge45 as their preferred partner, which says something about their technical credibility.
How to choose the right agency for your migration
Every migration is different. A domain change during a rebrand is not the same project as a Magento-to-Shopify move, and neither looks like a bilingual international expansion. Here is a simple way to narrow it down:
If you are doing an international rollout or working across multiple markets, Elixirr Digital or Delante are worth a close look. Both have demonstrated multi-market and multilingual work with documented results.
If you are a B2B brand migrating to or within WordPress, Hallam brings both the technical depth and the collaborative multi-team model that complex B2B sites tend to need.
If you are going through a rebrand and a migration simultaneously, Found's Clermont Hotel Group project is probably the most directly relevant published case study you will find from any agency on this list.
If your migration has already gone wrong and you need recovery work, Polaris and Edge45 both have published recovery case studies and specific recovery services.
If you want a technically precise partner that will treat your migration with the seriousness of a revenue-critical event, Edge45 is a strong fit, particularly for B2B and niche e-commerce.
For large, complex, or enterprise-level migrations with a lot of moving parts, Polaris's depth of published work and 5-stage framework make it the most thoroughly documented choice on this list.
Conclusion
Migrating a website without losing SEO is not about luck. It is about finding an agency that treats the pre-migration phase as seriously as the launch day, keeps monitoring active long after the new site is live, and has a published track record to back up what they promise.
The six agencies in this guide have all demonstrated they can handle complex SEO website migration projects and have case studies to prove it. Take the time to review their published work, ask to see examples relevant to your specific migration type, and make sure SEO is built into your timeline from the very beginning, not brought in as a last-minute check.
Frequently Asked Questions About Website Migration
How Long Does an SEO Website Migration Typically Take?
It depends on the size and complexity of your site, but most SEO migration projects run for one to two months from planning through post-launch monitoring. That timeline includes the pre-migration audit, redirect mapping, staging testing, and the critical post-launch monitoring period where issues tend to surface.
Will I Definitely Lose Traffic After I Migrate?
A small, temporary dip in traffic is common even after a well-executed migration. Google needs time to crawl, index, and re-evaluate your new site. The goal of working with an SEO migration agency is to minimize that dip and recover quickly, not to guarantee a zero-traffic-loss launch.
What Types of Migrations Have the Highest Risk?
Domain changes carry the most risk because they involve shifting your entire authority footprint to a new address. CMS migrations that also involve URL restructuring and a full redesign at the same time stack multiple risk factors together. The more variables that change at once, the more precisely the migration needs to be planned.
Should I Tell My SEO Agency About the Migration Before the Developers Start Building?
Yes, and the earlier the better. SEO needs to be embedded into the migration plan from the start, not reviewed after the new site is already built. Developers sometimes make structural decisions, such as URL changes, folder depth adjustments, or content consolidations, that have significant SEO implications.
What Happens If We Migrate and Things Go Wrong?
The sooner you identify the problem, the faster you can recover. The first step is not to panic and make rapid changes. Instead, work with your SEO team to run a crawl on both the old and new sites, check Google Search Console for coverage errors and indexing drops, and audit the redirect map for chains, loops, or missing mappings.
