--- title: "Best SEO migration agency: our top 10 agencies in France in 2026 - Astrak" url: "https://astrak.agency/en/best-seo-migration-agency/" lang: "en-US" --- Updated on **15/10/2026** · Agency sites reviewed on 15/10/2026 **What is the best agency for an SEO migration? On 15 October 2026 we reviewed the sites of about twenty agencies that handle redesigns, CMS changes and domain changes, and selected nine, ranked alongside Astrak.** A migration is judged on specific points: a redirect plan, testing in staging, follow-up after the switch, and cases where traffic held. That is what we looked for on each agency's site. Astrak is the author of this ranking and places itself first: the criteria are detailed below so you can judge for yourself. The leading trio ## Top 3 SEO migration agencies in 2026 [No. 1AstrakA six-step method published in full, from the redirect plan to the Go/NoGo before launch.](#fiche-astrak)[No. 2OnzeAbout ten published redesigns, from merging four country sites to migrating to WordPress.](#fiche-onze)[No. 3SlashrThe strongest migration evidence in the panel, up to 800,000 URLs redirected for a merger.](#fiche-slashr) ## SEO migration agencies in France: what each one publishes Instead of a score out of 10, the table shows what you actually find on each agency's site as of 15/10/2026. | Rank | Agency | Positioning | What the agency publishes about migration | Published price | |---|---|---|---|---| | 1 | Astrak | SEO and GEO agency · redesign, CMS change, testing and post-switch follow-up | 6-step method, more than 10 named deliverables, 3 migration and redesign case studies | Quote on request (3 to 5 months) | | 2 | Onze | SEO and GEO agency of senior consultants · redesigns and redirects | 4-step method, about ten redesign cases (SportEasy, Heytens, Decitre), redirect plan price | Redirect plan €650 to €1,300 | | 3 | Slashr | Search marketing agency, specialist in large URL volumes · Lille | 4-step method, in-house URL mapping tools, 3 quantified migration cases | 1k - 5k | | 4 | Résoneo | SEO, GEO and data consulting firm since 2004 · Paris | Support for CMS and domain changes, log analysis, Salomon case | 1k - 5k | | 5 | Eskimoz | European search acquisition group · Paris | 5-step method with staging tests, Crawlr tool, 3 redesign cases | 1k - 5k | | 6 | Uplix | SEO, paid media and data agency · Paris | 6-step protocol, named tools, free pre-migration risk analysis | 1k - 5k | | 7 | Empirik | SEO, GEO and data agency since 2012 · Lyon and Paris | Redesign cases for Legrand, Stormshield and Maréchal Fraîcheur; no migration page or method published | 1k - 5k | | 8 | Keyweo | Multilingual SEO, SEA and GEO agency · Barcelona | Migration method, DD Isolation and Kleta redesign cases | 1k - 5k | | 9 | SEO Hackers | SEO agency of senior consultants since 2012 · Paris | 5-step migration method (staging, logs), in-house tools, conference talks | 1k - 5k | | 10 | SEO Monkey | Acquisition agency, SEO first · Lille | Migration and redesign pages, timelines and prices, ImporteMoi and Lockall cases | Redesign from €3,000 · daily rate €500 | 1 ## [Astrak](https://astrak.agency/en/seo-redesign-agency/) SEO and GEO agency · redesign, CMS change, testing and post-switch follow-up ![Astrak Website](https://astrak.agency/wp-content/uploads/2026/10/Astrak-accueil-octobre-2026.jpg)Astrak is a French SEO and GEO agency of 13 people. Its page [SEO redesign agency](https://astrak.agency/en/seo-redesign-agency/) describes the engagement in six steps: scoping, semantic audit and cleanup before the redesign, SEO specifications adapted to the CMS and mockup approval, a URL-by-URL 301 redirect plan and template-by-template testing in staging, presence on launch day, then 30 to 45 days of follow-up comparing each URL with its previous data. Nothing goes to production without a formal Go/NoGo. The agency works directly with the developers, in a three-way relationship. The published cases cover several types of switch. [Centrale Autocar](https://astrak.agency/en/centrale-autocar-155-organic-traffic-12-months/) was taken over right after a migration to WordPress: +155% organic traffic in 13 months. At [Sixty8](https://astrak.agency/en/use-case-sixty8/), Astrak scoped the move of five stores to the latest version of PrestaShop, including a visual redesign: +42% organic clicks between summer 2025 and summer 2026. [Trackstone](https://astrak.agency/en/trackstone/) beat its records after a Google update. The method is detailed in our guide to the [SEO redirect plan](https://astrak.agency/en/redirection-plan/). #### Strengths - Full method published, with its deliverables: redirect plan, testing grid, post-switch report. - Formal Go/NoGo before release to production. - Direct work with your developers, no middleman. - Quantified, dated WordPress and PrestaShop migration cases. #### Points to watch - Price on quote: it depends on the number of templates and URLs to migrate. - No published case on a site with several million URLs. [Book an appointment with Astrak](https://astrak.agency/en/en/contact/#calendrier)2 ## [Onze](https://agenceonze.fr/services/refontes-seo/) SEO and GEO agency of senior consultants · redesigns and redirects ![Onze website](https://astrak.agency/wp-content/uploads/2026/10/classement-onze.jpg)Onze is an SEO and GEO agency founded in 2024 that only works with senior consultants, in pairs. Its redesign page describes four steps: upfront SEO strategy with functional wireframes given to designers, mockup review, a technical check of staging on more than 100 factors, then the 301 redirect plan. It recommends starting at least three months before launch. It is the agency in the panel that publishes the most redesign cases. SportEasy, which moved from an in-house build to WordPress with its blog brought back into a subfolder, recovered all its traffic in less than seven days. Heytens merged its four sites (France, Belgium, Luxembourg, Switzerland) in 2024 with no traffic loss, then gained 150% non-brand SEO traffic. Onze also led the merger of the Decitre and Furet du Nord sites. Its redirect plan is billed at €650 to €1,300. #### Strengths - Many redesign cases published, on several CMSs. - Involvement from the mockup stage, before development. - Redirect plan price listed. #### Points to watch - Figures sometimes differ between the redesign page and the case pages. - Several cases undated, two with no result published after launch. [See the SEO redesign offer](https://agenceonze.fr/services/refontes-seo/)3 ## [Slashr](https://agence-slashr.fr/seo/prestations/refonte-migration) Search marketing agency, specialist in large URL volumes · Lille ![Slashr website](https://astrak.agency/wp-content/uploads/2026/10/classement-slashr.jpg)Slashr is a Lille agency of ten consultants, founded in November 2021 by Anthony Lecas and Benoît Demonchaux, which makes migration one of its specialties: one to three months of preparation, in-house tools for automatic URL mapping, SEO testing in staging, then two to three months of follow-up after the switch. It also steps in to fix failed migrations, and advises against changing domain, CMS and URL structure at the same time when it can be avoided. Its most striking case is the merger of the US sites of Vestiaire Collective and Tradesy after the 2022 acquisition: 800,000 URLs redirected in six months, more than 160,000 of them prioritized, and the number of ranking keywords doubled. It also led the merger of Yakarouler and Carter Cash, with a content similarity script and log analysis, and recovered the failed migration of Les Petites Billes: +230% SEO traffic after the move back to WooCommerce. #### Strengths - Experience with very large URL volumes and site mergers. - In-house URL mapping tools. - Knows how to recover a failed migration. #### Points to watch - Small team for projects of this size. - Two cases published without a measurement date. [See the redesign and migration offer](https://agence-slashr.fr/seo/prestations/refonte-migration)4 ## [Résoneo](https://www.resoneo.com/nos-expertises/seo/) SEO, GEO and data consulting firm since 2004 · Paris ![Résoneo website](https://astrak.agency/wp-content/uploads/2026/10/classement-resoneo.jpg)Résoneo is a consulting firm founded in 2004 by Richard Strul and three partners, which now has more than 90 consultants and nine partners. It supports CMS changes, domain name changes and redesigns for large accounts: redirect plan and 301 rules, server log analysis, participation in design workshops, and server-side rendering recommendations for JavaScript sites. Among the platforms it masters, it cites Adobe Commerce, Salesforce Commerce Cloud, Drupal, PrestaShop, WordPress and Shopify. Its Salomon case study is the most impressive in the panel by scope: the replatforming of 25 e-commerce sites onto two CMSs, for +78% SEO traffic in one year. The client says it has worked with Résoneo since 2017 and carried out two replatformings with it. #### Strengths - Experience with multi-site, multi-country migrations for large accounts. - Log analysis and advanced technical SEO. - Team of more than 90 consultants. #### Points to watch - No offer page dedicated to migration. - Salomon case without precise dates. [See the SEO offer](https://www.resoneo.com/nos-expertises/seo/)5 ## [Eskimoz](https://www.eskimoz.fr/refonte-site-internet/) European search acquisition group · Paris ![Eskimoz Website](https://astrak.agency/wp-content/uploads/2026/10/classement-eskimoz.jpg)Eskimoz is a search acquisition group of more than 250 consultants, based in Paris, Madrid, Düsseldorf, Milan and London, which claims more than 1,000 clients and works in ten languages. Its redesign offer covers site mergers, CMS changes and visual redesigns, in five steps: technical specifications, mockup audit, staging audit, redirect plan and testing before release, with its in-house Crawlr crawler. It publishes three cases: Mailinblack (+54% organic traffic and +37% leads from SEO after a full redesign), Combo (secured migration to Webflow, +232% organic traffic) and PwC (redesign of its French-language sites, +109% organic traffic). Part of its fee is tied to performance. #### Strengths - Ability to handle multi-country and multilingual projects. - Staging tests at the core of the method. - Three redesign cases published. #### Points to watch - Undated results, mixing migration, content and link building. - No price for redesigns, only ranges for SEO support. [See the redesign offer](https://www.eskimoz.fr/refonte-site-internet/)6 ## [Uplix](https://www.uplix.fr/agence-seo/migration-seo/) SEO, paid media and data agency · Paris ![Uplix website](https://astrak.agency/wp-content/uploads/2026/10/classement-uplix.jpg)Uplix is a Paris agency that combines SEO, advertising and data, winner of the Grand Prix Digital at the Cas d'Or in the Search and AI category. Its migration page describes a six-step protocol, presented as proven on dozens of projects: scoping, inventory of all URLs ranked by SEO value, mockup and staging audit, 301 redirect matrix, final testing (source code, sitemap, internal linking, redirects, metadata) and follow-up after launch. The tools are named (Screaming Frog, Search Console, Google Analytics), and the agency offers a free pre-migration risk analysis with its consulting director, useful to gauge what is at stake before signing. It cites Acadomia among its successful migrations. #### Strengths - Clear protocol, from inventory to follow-up. - Free risk analysis before the project. - Data culture and proprietary tools. #### Points to watch - Migration results not very detailed. - No team size or prices published. [See the SEO migration offer](https://www.uplix.fr/agence-seo/migration-seo/)7 ## [Empirik](https://www.empirik.fr/nos-ressources/etudes-de-cas/etude-de-cas-legrand/) SEO, GEO and data agency since 2012 · Lyon and Paris ![Empirik website](https://astrak.agency/wp-content/uploads/2026/10/classement-empirik.jpg)Empirik is a digital marketing agency founded in Lyon in 2012 by Lionel Cherpin, also based in Paris, with 23 staff across SEO, GEO, advertising, analytics and conversion. It works for Legrand, Yves Rocher, Peugeot, Cointreau and Stormshield, and has developed about twenty in-house tools, including the Impakkt platform and AI citation tracking. What is missing first: Empirik has no page dedicated to migration. Redesign support is part of its SEO offer, and its audit page recommends an audit and a redirect plan before any redesign, without detailing the method further. Its cases are telling, though. At Legrand, the agency audited the redesign, approved the prototypes and handled the SEO transfer: on the same scope, traffic held after launch, with +20% keywords at the top of results in France. It also supported the redesign of Stormshield's multilingual site, and Maréchal Fraîcheur reports a migration of its e-commerce site followed by +481% visits in one year. #### Strengths - Redesigns of major brands with no traffic loss. - Audit and redirect plan recommended before the switch. - Experience with multilingual sites. #### Points to watch - No migration page or method published. - Old or undated cases (the Legrand case was published in 2018). - No published prices. [See the Legrand case](https://www.empirik.fr/nos-ressources/etudes-de-cas/etude-de-cas-legrand/)8 ## [Keyweo](https://www.keyweo.com/fr/seo/services/migration-seo/) Multilingual SEO, SEA and GEO agency · Barcelona ![Keyweo website](https://astrak.agency/wp-content/uploads/2026/10/classement-keyweo.jpg)Keyweo is an SEO, SEA and GEO agency founded in 2018 in Barcelona by two French entrepreneurs, Guillaume Bonnard and Guillaume Peltier. Its team, of seven nationalities, works on nearly twelve markets and writes in several languages. Its migration page follows a classic sequence: goals, SEO check of both versions of the site, URL mapping and migration plan, presence on switch day, redirect checks and KPI tracking. It publishes two redesign cases: DD Isolation, in Belgium, with +140% clicks one year after its site redesign, and Kleta, in Spain, with +227% non-brand clicks between December 2022 and December 2023. #### Strengths - Quantified redesign cases, across several countries. - Migration method described. - Multilingual team for international sites. #### Points to watch - No case details the redirect plan. - No price for migration. [See the SEO migration offer](https://www.keyweo.com/fr/seo/services/migration-seo/)9 ## [SEO Hackers](https://seohackers.fr/seo/refonte-de-site-migration/) SEO agency of senior consultants since 2012 · Paris ![SEO Hackers website](https://astrak.agency/wp-content/uploads/2026/10/classement-seo-hackers.jpg)SEO Hackers is a Paris agency founded in 2012 by Paul Sanches and Mathieu Gheerbrant, both in SEO since 2006. It has nine senior consultants, with seven to twenty years of experience, claims more than 500 clients, from small businesses to CAC 40 groups, and builds its own tools, such as Kill Duplicate against copied content and InternalDup for internal duplication. Its redesign and migration page covers changes of design, CMS, domain name or hosting, in five steps: pre-migration audit (URLs, high-traffic pages, backlinks), a new URL structure that keeps as much of the existing one as possible, a complete 301 redirect file, tests of all redirects on a staging server, then monitoring after the switch in Search Console, analytics and server logs. Its founders speak regularly at SMX Paris and SEO Camp'us. #### Strengths - Full migration method, staging and logs included. - Senior consultants only. - Tools developed in-house. #### Points to watch - No migration case published. - Prices not listed. [See the redesign and migration offer](https://seohackers.fr/seo/refonte-de-site-migration/)10 ## [SEO Monkey](https://www.seo-monkey.fr/seo/migration-seo/) Acquisition agency, SEO first · Lille ![SEO Monkey Website](https://astrak.agency/wp-content/uploads/2026/10/classement-seo-monkey.jpg)SEO Monkey is an acquisition agency founded in Lille in 2020 by Antoine Veyrières, with SEO as its core business. It claims more than 400 companies served and has built its own tools, including a crawler, Crawlr. Its migration page covers the pre-switch audit, 301 redirects, sitemaps, carrying over structured data and monitoring in Search Console, over two to six weeks; a supported redesign starts at €3,000 and lasts one to three months. Its ImporteMoi case details a migration in three phases: preparation (URL mapping, redirect plan, technical specifications), technical support with redirect tests in staging, then testing by crawl before launch. For Lockall, a redesign was followed by +76% traffic in twelve months and first place on "location box ile de france". #### Strengths - Redesign prices and timelines listed. - Migration method described step by step. - Tools developed in-house. #### Points to watch - No migration case with a before/after comparison. - Several recent case studies are launches, with no results yet. [See the SEO migration offer](https://www.seo-monkey.fr/seo/migration-seo/) ## Agencies we reviewed but left out About twenty agencies were reviewed. Peak Ace, which absorbed Search Foresight, has a real technical pedigree but no longer highlights a migration offer or a published case. Datashake, ranked first for migration in a third-party ranking, does not mention migration on its own site. SeoMix is an excellent specialist in WordPress migrations, which we rank in our [top WordPress SEO agencies](https://astrak.agency/en/best-wordpress-seo-agency/). Premiere.Page lists a clear entry price (€1,980 excl. VAT) but its cases are about small sites. Yumens has a sound method with no visible specialization. Junto, Noiise and Passedevant have a real migration offer, but do not yet publish a quantified migration case. Pixalione delivers its redirects as a server file ready to install and publishes one case (Autobacs); it just misses this top 10, as does L'Agence WAM, whose migration method is one of the most detailed on the market. ## The steps of a successful SEO migration A site migration (redesign, change of CMS, domain or URL structure) is the riskiest moment for SEO. Losses almost always come from the same oversights. A serious agency follows a plan close to this one. Before ### The inventory All the URLs that matter: pages that get clicks, external links or visits. You pull them from Search Console, analytics, the backlink tool and a full crawl, then save this baseline data. Before ### The redirect plan Each old URL redirects with a 301 to its equivalent page on the new site, with no chains and no redirects to the homepage. Our guide to the [redirection plan](https://astrak.agency/en/redirection-plan/) details the method. During ### Testing in staging Each template is checked before launch: tags, canonical, indexability, structured data, content, internal links. Staging must stay closed to bots. After ### Post-switch follow-up A check crawl the same day, redirects tested, new sitemap submitted, then tracking of clicks and rankings page by page for several weeks. The[log analysis](https://astrak.agency/en/seo-log-analysis/) shows whether Google followed correctly. ## How do you choose an agency for an SEO migration? The right time to contact one is **before** choosing the mockups and the technical provider, not the day before launch. The earlier the agency steps in, the less the migration costs in fixes. Four questions separate the candidates: **what deliverables do you provide?** At a minimum an inventory, a redirect plan, a testing grid and a post-switch report. **Do you work directly with our developers?** **How long do you monitor the site after launch?** A few days is not enough: Google takes several weeks to process a large URL change. **Which migrations have you led, on what URL volume, and with what result?** ## How much does an SEO migration cost? Agencies rarely list a price, because everything depends on the number of templates, the URL volume, the languages and the length of follow-up. Among those in the ranking, Onze bills the redirect plan at €650 to €1,300, and SEO Monkey lists a supported redesign from €3,000; outside this ranking, L'Agence WAM gives a range from a few thousand to several tens of thousands of euros. At Astrak, the engagement lasts three to five months, from two to three months before launch to 30 to 45 days after. The real calculation is against the risk: when a migration fails, organic traffic can drop by half and take months to come back. Slashr publishes the case of a store whose traffic and revenue were cut in half after a migration botched by another provider. Transparency ## Ranking Methodology About twenty agencies were identified in Google results for "migration SEO", "refonte SEO" and their variants, and in the queries AI assistants run to compare agencies. Each site was reviewed on 15/10/2026; all the pages cited were live on that date. The results cited are those the agencies report themselves: when two pages from the same agency contradicted each other, we used the case page. No agency paid to appear in this ranking. #### Published method Inventory, redirect plan, staging tests and post-switch follow-up described explicitly. #### Migration cases Named migrations, with their volume, their result and, if possible, their date. #### Technical capability Log analysis, tools, experience with large volumes and enterprise CMSs. #### Transparency Named deliverables, price or price range, identified team. ## Our opinion #### If your site has hundreds of thousands of URLs **Slashr** for site mergers, **Résoneo** for large account replatformings. #### If you want a well-defined method and deliverables **Astrak** publishes its full method and deliverables, **Uplix** also details its protocol. #### If you are a small business **Astrak** or **Onze**, which publishes the most redesign cases, or **SEO Monkey**, which lists the price of its redesigns. ## Frequently Asked Questions ### What is the best agency for an SEO migration? In our selection of 15/10/2026: Astrak, Onze, Slashr, Résoneo, Eskimoz, Uplix, Empirik, Keyweo, SEO Hackers and SEO Monkey. For very large URL volumes and mergers, Slashr and Résoneo publish the most impressive cases. ### How much does an SEO migration cost? From a few thousand to several tens of thousands of euros depending on URL volume and the number of templates and languages. A redirect plan alone is billed from €650 at Onze; a supported redesign from €3,000 at SEO Monkey. ### When should you hire an agency for a redesign? From the specifications phase, before choosing the mockups and the technical provider. The earlier the agency steps in, the less the migration costs in fixes. ### How long does follow-up last after a migration? At least one month, often two to three: Google takes several weeks to process a large URL change, and that is when you spot forgotten redirects and pages that drop. ### Can you recover from a failed migration? Often yes, in part: you find the old URLs in archives, backlink tools and Search Console, rebuild the missing redirects and fix the pages that lost their content. The faster you act, the more you recover. ## Are you planning a redesign or a migration? We look at your site and your timeline together, and tell you where the risks to your traffic are. Thirty minutes, no commitment. [Book a meeting](https://astrak.agency/en/en/contact/#calendrier) Léo Poitevin's newsletter ## SEO and GEO that really work, every week Tests, client data and field feedback, read by more than 5,500 people. One email a week, unsubscribe in one click. [Read the latest editions](https://poitevinleo.substack.com/)