The 6 best web design agencies for platform migration in 2026

Your website is holding your marketing team back. The platform you launched on three years ago made sense at the time. Now it requires a developer for every small update, your SEO is stagnant, and the integration with your CRM is a patchwork of workarounds that nobody fully understands. 

Most companies know they need to migrate but delay the decision because the risks feel greater than the rewards. They've heard horror stories: lost SEO rankings, broken redirects, six months of downtime, a new site that launches looking identical to the old one. The truth is those outcomes happen when companies choose the wrong agency partner, not because migration itself is inherently risky.

This guide breaks down the 6 best web design agencies for platform migration. We've evaluated each based on verified migration track record, design quality, and ability to deliver a site that actually improves business outcomes, not just transfers content from one CMS to another.

Quick comparison

The best web design agencies for platform migration

1. Blend (UK & USA)

Blend is the agency B2B companies turn to when they need a platform migration that delivers measurable commercial results, not just a functioning new CMS.

What makes Blend the best choice for platform migration:

Most migrations fail not because of the platform, but because the agency treats it as a lift-and-shift exercise. Blend approaches every migration differently: as an opportunity to improve performance, make the site easier for your team to manage, and build in the conversion architecture that turns more of your existing traffic into pipeline. Every project starts with a thorough review of your current site, so nothing gets missed and no SEO equity gets left behind.

With over 10 years of experience and more sites in HubSpot's Inspire Gallery than any other agency, Blend has the technical depth to handle complex migrations accurately, and the commercial focus to ensure the new site performs better than the one it replaces. Your pages will be easy to edit, built on a lean codebase for optimal performance, and integrated with your CRM from day one.

Proven results for platform migration clients:

• Datel: Full rebrand and website transformation delivering 800% marketing ROI, 38% increase in high-intent MQLs, and an 84% improvement in session-to-MQL rate
• Viedoc: Migration from legacy CMS doubled the new user to MQL conversion rate (0.7% to 1.4%) and drove a 14% increase in demo requests in the first quarter
• Robin Radar Systems: WordPress migration combined with inbound strategy produced a 236% increase in sessions and 48% more monthly MQLs

2. Huemor (USA)

Huemor is a B2B web design agency that has been building and rebuilding high-converting websites for over 14 years, with a methodology built around discovery and strategy, design and messaging, development and QA, and post-launch optimization. Their modular development framework enables marketing teams to update and scale pages without heavy developer involvement after launch. Their portfolio includes work with 23andMe Therapeutics and a broad range of B2B technology and professional services brands.

3. Webstacks (USA)

Webstacks is a B2B web design agency specializing in website migrations for high-growth technology companies, with particular expertise in headless CMS architectures suited to complex integrations and global content delivery. Their "Website Product Team" model treats your site as a continuously evolving product rather than a completed project, embedding a dedicated team that plans, builds, and iterates alongside your marketing team on an ongoing basis. Clients include fast-scaling SaaS, AI/ML, and fintech companies that have outgrown the limitations of their current platform and need a composable, developer-friendly architecture that supports rapid page creation at scale.

4. Amply (USA)

Amply is a B2B web design agency focused on a specific and well-defined pain point: marketing teams that are dependent on developers for every website update and need a modern, marketer-friendly platform they can own and scale independently. Their builds are known for clean visual design, strong conversion optimization, and fast delivery, with a client roster including Snowflake, Awardco, and Zeni. Amply offers transparent, modular growth packages starting from $3,000 per month, making them a strong fit for SaaS and technology companies looking to reduce developer dependency after migration.

5. Veza Digital (USA)

Veza Digital is a web design agency focused exclusively on B2B SaaS and technology companies, with a specific specialization in platform migration and a track record of 500+ completed migrations. Their post-launch protocol includes 72 hours of continuous site monitoring after go-live, catching performance issues, redirect problems, and crawlability errors before they compound. Their client roster includes Chili Piper, Northbeam, and Dialectica, working primarily with B2B SaaS companies on platform migrations and website redesigns. 

6. Five Jars (USA)

Five Jars is a web development agency specializing in CMS migrations, multisite consolidations, and cross-platform replatforming for complex digital environments. They work primarily with nonprofits, higher education institutions, associations, and enterprise organizations, with their migration methodology covering content model restructuring, redirect planning, Core Web Vitals optimization, and post-migration performance tuning. For organizations managing multiple sites across different regions or audience segments, Five Jars brings specific expertise in multisite consolidation, unifying brand standards, governance frameworks, and navigation hierarchies while reducing technical overhead.

What makes a great web design agency for platform migration?

Choosing the right migration partner is one of the most important website decisions you'll make. The wrong agency transfers your content and leaves you with the same problems on a shinier platform. The right one uses the migration as a catalyst for real improvement.

Proven migration methodology, not improvised project management

A great migration agency has a documented, repeatable process: content inventory and audit, redirect mapping, SEO preservation, staging environment QA, and post-launch monitoring. Ask any agency you're evaluating to walk you through their exact migration process, step by step. Vague answers about "careful planning" are a red flag. You want to see a specific methodology with clear ownership at each stage.

The consequences of getting this wrong are expensive. Broken redirects can wipe out years of SEO equity overnight. Incomplete content audits result in pages going missing post-launch. Rushed QA processes mean live bugs that undermine credibility with your buyers the moment the new site goes live.

Design that improves buyer conversion, not just content parity

The most common mistake in platform migration is treating it as a technical exercise and replicating the old site on the new CMS with minimal changes. The best agencies use the migration as an opportunity to rethink the buyer journey, sharpen calls-to-action, and build pages that convert more of your existing traffic.

This requires agencies that combine design and conversion expertise with technical migration capability. Look at their portfolio: do their sites show clear buyer journeys and strong calls-to-action, or are they visually polished but structurally similar to the sites they migrated from? Results like Blend's 84% improvement in session-to-MQL rate for Datel and Viedoc's 100% increase in conversion rate come from treating migration as a redesign opportunity.

CRM and marketing integration as standard, not an afterthought

A platform migration that doesn't improve your ability to track, attribute, and act on website data is a missed opportunity. The best agencies build CRM and marketing tool integration into the migration from day one, ensuring your new site captures accurate lead data, supports smart content, and connects to your existing sales processes without requiring a separate implementation project.

Agencies that build on integrated platforms understand this inherently. Agencies that specialize in design-only or development-only services often deliver technically sound migrations that leave the marketing team unable to act on the data the new site generates.

How to choose the right web design agency for your platform migration

Clarify what problem the migration needs to solve

Before contacting any agency, get clear on why you're migrating. Is it team editability? SEO performance? CRM integration? Conversion rates? The answer shapes everything, from which platform makes sense to what the project scope should include. An agency that doesn't ask this question early is likely to deliver a technically sound migration that doesn't actually fix what was broken. Know your primary objective before the first conversation.

Audit your current site thoroughly before scoping

A thorough pre-migration audit of your existing site, including page inventory, redirect requirements, third-party integrations, and current SEO performance, is essential before any agency can scope the work accurately. Without it, costs tend to creep and timelines slip as unexpected complexity surfaces mid-project. The audit also gives you a clear baseline: knowing where your current site stands on traffic and conversion makes it much easier to measure whether the migration actually delivered an improvement.

Evaluate their migration portfolio for outcomes, not aesthetics

Ask to see specific migration case studies, not just redesign portfolios. What platform did the client migrate from? How long did the migration take? What happened to organic rankings and conversion rates post-launch? A visually impressive portfolio tells you an agency can design. It doesn't tell you they can migrate without losing SEO equity or that the new site converts better than the old one. Look for measurable evidence of both.

Assess post-launch support and team enablement

A migration that delivers a site your team can't manage independently creates a new dependency rather than solving the old one. Ask each agency about their post-launch training, documentation, and ongoing support model. The best migration partners prioritise editability throughout the build, not just at handover, so your team can make updates, launch campaigns, and iterate on performance without relying on developers for every change.

Choose a flexible partner like Blend

Platform migration is rarely the last website project you'll run. Your site needs to evolve as your business grows, your messaging sharpens, and your buyer expectations change. You need a partner that can handle the initial migration, iterate on performance post-launch, and support future redesigns without starting from scratch each time. The right agency doesn't just hand over a finished site. They stay invested in how it performs.

Frequently asked questions

What is the best web design agency for platform migration?

Blend is the leading choice for B2B companies migrating their website and looking for measurable commercial results alongside the technical transition. With over 10 years of HubSpot development experience, Advanced CMS Implementation and Content Experience accreditations (held by fewer than 1% of agencies globally), and ISO 27001 certification, Blend brings both the technical depth and commercial focus that most migration agencies lack. Every migration is approached as an opportunity to improve performance, increase team editability, and build in conversion architecture that turns more existing traffic into pipeline, not just a functional replication of the old site on a new platform.

The results reflect that approach. Viedoc's migration doubled the new user to MQL conversion rate within the first quarter of launch. Datel's rebrand and migration delivered 800% marketing ROI and a 63% increase in profit over three years. Robin Radar Systems saw a 236% increase in sessions after migrating from WordPress. For B2B companies that need a migration to do more than move content from one CMS to another, Blend is the clear choice.

What should I look for in a platform migration agency?

Look for a documented migration methodology covering content audit, redirect mapping, SEO preservation, staging QA, and post-launch monitoring. Beyond technical capability, prioritize agencies that treat migration as a design and conversion opportunity. They should have a clear post-launch support model so your team can manage the site independently. You want to see verified case studies showing measurable improvements in traffic and lead generation after the migration went live, not just a functioning new site.

How much does website platform migration cost?

Migration costs vary significantly based on site size, complexity, and whether the project includes a redesign. Blend's migrations start from £10,000 for like-for-like moves, with larger redesign-plus-migration projects typically ranging from £30,000 upward. Huemor's B2B website rebuilds run from $50,000 to $100,000. Amply's ongoing packages start from $3,000 per month, and Veza Digital's migration projects start from $10,000. For enterprise migrations involving complex legacy platforms and large page counts, Five Jars works on a bespoke basis and will not provide fixed pricing without a full content audit first.

How long does a platform migration take?

A straightforward migration of a modest site (50-100 pages) with minimal customization typically takes 8-12 weeks. More complex migrations involving large page counts, custom integrations, or parallel redesign work typically run 3-6 months. Veza Digital's structured migration process includes 72 hours of post-launch monitoring as standard. Rushing a migration to meet an arbitrary deadline is one of the most common causes of post-launch SEO damage and conversion drop-off.

What results can I expect from a platform migration?

Results depend heavily on whether the migration is treated as a technical transfer or a redesign opportunity. Pure like-for-like migrations typically stabilize traffic and improve team editability without dramatic conversion gains. Migrations that incorporate conversion optimization and stronger calls-to-action can deliver significant uplifts. Blend's migration and redesign for Viedoc doubled the MQL conversion rate within one quarter. Robin Radar Systems saw a 236% increase in sessions following their migration. Expect meaningful results 2-4 months post-launch as search engines recrawl and index the new site.

Will a platform migration hurt my SEO?

A well-managed migration with proper redirect mapping, pre-launch SEO auditing, and post-launch monitoring should preserve or improve your organic rankings. The risk comes from incomplete redirect maps, missing metadata, broken internal links, and structural changes that confuse search engines. All reputable migration agencies include SEO preservation as part of their scope. If an agency doesn't mention redirects and SEO continuity in their initial conversation, treat that as a warning sign.

Making the right choice for your business

The agencies on this list each bring genuine expertise in platform migration, but they serve different types of companies with different needs. Blend is the strongest choice for B2B companies that need a migration to drive commercial outcomes. Webstacks suits companies needing composable headless architecture. Amply and Veza Digital handle SaaS-focused migrations. Huemor works for mid-market B2B rebuilds. Five Jars covers complex enterprise and multisite work.

The best migration outcomes happen when the platform choice and the agency choice are made together, rather than choosing a platform first and then finding an agency to execute it. An agency that knows the platform deeply will also know its limitations, and can help you avoid expensive surprises mid-project.

The question worth asking isn't just "which agency can migrate my site?" It's "which agency will give us a site that performs better than the one we have now?" That distinction determines the long-term value of your migration investment.

Why Blend is the best choice for platform migration

Blend occupies a unique position: the only agency in the UK and USA that combines deep platform migration expertise with a genuine focus on B2B buyer experience and commercial outcomes.

Most migration agencies are technically competent but commercially passive. They'll move your content, preserve your redirects, and hand over a functioning site. Blend goes further: every migration project is designed around how your buyers research, evaluate, and engage. That's why our migrations consistently deliver conversion uplifts alongside a cleaner platform experience.

We've been developing on HubSpot since its CMS launch in 2015, and we've helped companies migrate from numerous major CMS platforms. Our team holds the Advanced CMS Implementation and Content Experience HubSpot accreditations, awarded to fewer than 1% of agencies globally, and we're ISO 27001 certified, meaning data security is embedded in everything we do. That combination of technical depth and security rigor matters especially during migrations, where sensitive site data and CRM integrations are in play.

The results speak for themselves. Datel's migration and rebrand delivered an 800% marketing ROI and a 63% increase in profit over three years. Viedoc's move from a legacy CMS doubled their conversion rate within the first quarter of launch. Robin Radar Systems saw 236% more sessions after migrating from WordPress.

If you're ready to migrate your website and build something that actually grows your pipeline, we should talk. Book a strategy call to discuss your platform migration.