Top 10 frontend modernization companies in 2026, judged on the migrations they published

Last updated: 16 october 2026. Data: 4,097 vendor modernization case studies collected in September 2026.

We read 4,097 modernization case studies published on the websites of 461 vendors listed in Clutch's application modernization category. Only 31 of them, from 23 vendors, name the legacy frontend framework the team moved off and what it moved to. Every other "frontend modernization" claim in that pile is a redesign, a new build, or a backend job with a fresh coat of paint on the screens.

Brocoders wrote this list, and we sell modernization work ourselves, so we left ourselves out of the ranking and explain our own record in the methodology section. We ranked the vendors who published a real frontend migration on one test we call The Live Frontend Migration Test: did the team move a named legacy framework, keep the product shipping, and come back with a number?

TL;DR: The 10 companies with the strongest published frontend migrations are Hotovo, Aimprosoft, Squash Apps, Valor Software, UppLabs, SitePen, Celestial Systems, Code District, Rishabh Software and ElifTech. Ext JS (11 case studies), ASP.NET Web Forms (8) and AngularJS (7) are the legacy front ends vendors document most. Judge a partner on five signals: a named legacy framework, a product that kept shipping, an incremental path, a number after the move, and a team that stayed.

Table of Contents
The Live Frontend Migration Test: five signals that predict a safe migration
Quick comparison table
Research methodology and how this list was made
1. Hotovo: screen-by-screen migrations with AI-assisted refactoring
2. Aimprosoft: gradual jQuery to Vue.js migration on a 19-year-old platform
3. Squash Apps: jQuery to React inside a live healthtech SaaS
4. Valor Software: AngularJS to Angular migrations, split into maintainable apps
5. UppLabs: four frontend generations on one product, with no service interruption
6. SitePen: incremental Dojo Toolkit to React for enterprise web clients
7. Celestial Systems: Ext JS specialists for regulated front ends
8. Code District: Angular to Next.js with a growth number
9. Rishabh Software: Silverlight to Angular for government workflows
10. ElifTech: AngularJS to React with a team that stayed
What the data says about frontend migrations
How to choose a frontend modernization partner
Cost and pricing
Conclusion

The Live Frontend Migration Test: five signals that predict a safe migration

A frontend migration succeeds when users keep working and the team keeps releasing while the old framework disappears screen by screen. A vendor's star rating and framework logos say nothing about that. These five signals do, and every company below is scored on them.

1. A named legacy framework. The case study says what the team moved off (AngularJS, jQuery, Ext JS, Dojo, Silverlight, Web Forms) and what it moved to. "Modernized the UI" without a framework name usually means a redesign.

2. The product kept shipping. The vendor states that feature work or service continued during the migration. A frontend freeze of 9 months is the most expensive way to modernize, because the business pays for two products and gets new features from neither.

3. An incremental path. Look for screen-by-screen replacement, interop between the old and new framework, or a split into smaller apps. A full rewrite that ships on one date carries the risk of every bug landing at once.

4. A number after the move. Load time, release frequency, bug rate, active users or developer hours. A migration with no measured result gives you nothing to hold the next vendor to.

5. The team stayed. A vendor that still runs the product years later lived with its own architecture decisions. That is the closest thing to a warranty this market offers.

Quick comparison table

Ratings, rates and minimums come from Clutch profiles as collected in September 2026. Check each on the live profile before you shortlist.

Research methodology and how this list was made

Brocoders wrote this page. We sell application modernization services, so you should know who is doing the judging. No vendor paid to be listed, and we did not copy from other listicles.

The data. In September 2026 we collected the 4,215 provider profiles in Clutch's application modernization category, their client reviews, and the case studies each vendor publishes on its own website. Of 7,934 case studies, 4,097 describe modernization work, from 461 vendors. We searched them for a sentence that names a legacy frontend framework next to a migration verb (migrated, replaced, rewrote, upgraded, transitioned). That left 31 case studies from 23 vendors. We then read each one, plus the vendor's Clutch reviews, by hand.

The selection. We kept the 10 vendors whose published work gives the most evidence on The Live Frontend Migration Test, one point per signal. Ties are ordered by the strength of the published numbers. Every claim in a profile comes from the vendor's own case study page or its Clutch profile, linked in that profile. "Best for" lines are our editorial reading of that evidence.

The limits. The dataset covers vendors listed in one Clutch category. A frontend-only studio outside that category, or a vendor that keeps its migrations under NDA, does not show up here. A low score means the vendor has not published the evidence, which is different from not having done the work.

Where Brocoders stands on the same test. Our frontend modernization record sits inside larger engagements. For PayPilot, a payroll software company, we ran a React frontend team of up to 15 engineers inside the client's own rebuild from February 2022 to March 2026, while the client owned the backend. For Beyondgreen, a school-lunch ordering service built on legacy technologies that produced incorrect financial reports, we rebuilt the platform on React and Node.js. For Adact, we restructured a working MVP for high load, rebuilt its core on Node.js and React, and shipped the first version of the rebuild in about 6 months. None of our published cases names a legacy frontend framework we moved off, so under signal 1 we would not score high enough for this list.

1. Hotovo: screen-by-screen migrations with AI-assisted refactoring

Sources: Clutch profile, Protecht migration case study, Akixi case study

Hotovo, founded in Košice in 2010, lists enterprise app modernization as 20% of its service mix on Clutch. Its published work centers on long engagements with software companies whose web clients predate React.

Protecht's enterprise risk management platform ran on a Java web stack that Hotovo's earlier Protecht case lists as JSP, GWT and Sencha GXT. Hotovo migrated a large set of its UI screens to React and TypeScript with a 1:1 design approach. The 10-developer team ran migration and new features on parallel tracks, used a React component library it had refined over 5 years, and reported up to 60%+ higher developer efficiency from AI-assisted refactoring, with no disruption to product development.

For Akixi, a call analytics company, Hotovo has worked for more than 4 years across mobile, server-side and the web front end, including the move from legacy technologies to a modern front-end stack. "We've been working with the Hotovo team for over 4 years on a wide-range of projects," said Martin Waters, Technical Director at Akixi.

Test score: 5 of 5. Named legacy stack, parallel feature work, screen-by-screen path, a published number, and a multi-year team.

Honest weakness: Hotovo holds only 4 Clutch reviews, and its headline number measures developer efficiency, so you get no published user-facing result such as load time.

Best for: software companies with a large Java-era web client (GWT, Ext JS family) that must keep shipping features during a React migration.

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2. Aimprosoft: gradual jQuery to Vue.js migration on a 19-year-old platform

Sources: Clutch profile, Orbis case study, Genesys case study

Aimprosoft, founded in 2005, lists enterprise app modernization as 15% of its Clutch service mix. Its strongest frontend evidence comes from a platform that had grown for 19 years before the team arrived.

Aimprosoft replaced jQuery with Vue.js in Orbis's career and work-placement platform for Canadian colleges and universities, one module at a time, while it also moved the backend from Spring 2 and Hibernate 2 to version 6. Orbis kept adding features and deploying fixes without downtime, and the platform now handles 70,000+ page loads per day.

The engagement has run since May 2020 with 2 frontend and 3 full-stack developers. For the Crop Trust's Genesys biodiversity platform, the team rebuilt the backend from PHP to Java and rebuilt the front end in React. Emily Eley, VP of Operations and People at Orbis, describes the relationship as "built on a strong foundation of communication, trust, and strong deliverables."

Test score: 5 of 5. Named framework pair, no downtime, a module-by-module path, a traffic number, and a 6-year team.

Honest weakness: the Orbis numbers describe platform traffic and backend upgrades, so no published figure isolates what the Vue.js migration changed for users.

Best for: education and other long-lived platforms where the frontend and the backend frameworks both need upgrading without a cutover date.

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3. Squash Apps: jQuery to React inside a live healthtech SaaS

Sources: Clutch profile, HealthTech SaaS case study

Squash Apps, founded in 2015, holds a 5.0 Clutch rating across 21 reviews. Its published migration sits inside a team-extension engagement for an Australian healthtech SaaS with 2 in-house engineers.

Squash Apps moved the appointment scheduling interface, the most-used part of the platform, from a jQuery-based implementation to a React component architecture. The work ran alongside a new CI/CD pipeline and test coverage, and releases went from about 1 per month to weekly within 4 months, while the bug escape rate per deployment fell by 50%.

The team grew from 2 to 12 engineers over the 18-month engagement, which is still running. "They rebuilt our engineering foundation while simultaneously shipping product," said the client's CTO.

Test score: 5 of 5. Named framework pair, product shipped throughout, one module at a time, release and bug numbers, and a team still in place.

Honest weakness: the jQuery to React work covers 1 interface inside a broader engagement, and the client is unnamed, so you cannot check the reference yourself.

Best for: SaaS companies with a small in-house team that need the busiest legacy screens moved to React while release frequency goes up.

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4. Valor Software: AngularJS to Angular migrations, split into maintainable apps

Sources: Clutch profile, Terminus case study, TablesReady case study, CareerBuilder case study

Valor Software, founded in 2013, holds a 5.0 Clutch rating across 20 reviews and publishes 3 Angular modernization cases.

For Terminus, Valor split Data Studio and Measurement Studio, 1 AngularJS application with a shared codebase, into 2 applications and migrated both to Angular, organized as Nx libraries. The result was a lighter codebase with reusable components and 90% unit test coverage.

TablesReady, a hospitality app for managing guest lines, has worked with Valor for more than 7 years, through moves from AngularJS to Angular, PHP to Node.js and MongoDB to PostgreSQL. At CareerBuilder, Valor re-architected the front end into micro-frontends. "The attitude of fully integrating with the team and behaving as a co-owner of the platform was a refreshing departure from classical off shore," said Zackary Chapple, Principal Architect at CareerBuilder.

Test score: 4 of 5. Named framework pair, a split-app path, a test coverage number, and a 7-year client. No case states that feature work continued during the migration.

Honest weakness: Valor's published evidence is Angular-heavy, so a team moving to React or Vue gets less proof from its portfolio.

Best for: products still on AngularJS that want to stay in the Angular ecosystem and come out with a modular, tested codebase.

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5. UppLabs: four frontend generations on one product, with no service interruption

Sources: Clutch profile, List Assist case study

UppLabs, founded in 2014, holds a 4.9 Clutch rating across 18 reviews. Its frontend case is one of the longest migration records in the dataset.

UppLabs took over MMI Direct's List Assist marketing data platform after another team failed the project, then moved its front end from ASP.NET Web Forms to ASP.NET MVC, then to Angular, and now to React, without any service interruption. The platform processes 10M+ records with custom filtering for each client.

The partnership has run since 2014, with a team of 6: 1 frontend developer, 2 backend developers, 1 PM and 2 QA engineers. "UppLabs excels at meeting deadlines and sticking to priorities, consistently delivering quality work on time," said Lori Barao, Manager of Operations at MMI Direct.

Test score: 4 of 5. Named frameworks, no interruption, a staged path across 3 moves, and a 10-year team. The published number describes data volume, so it does not count as a frontend result.

Honest weakness: a single frontend developer on the team means a large screen count would move slowly, and Clutch lists no headquarters for UppLabs.

Best for: owners of a takeover or rescue product on .NET Web Forms who need a long-term team to retire the old UI in stages.

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6. SitePen: incremental Dojo Toolkit to React for enterprise web clients

Sources: Clutch profile, Centric Software case study, Marriott case study

SitePen, founded in 2000, describes itself as an active contributor to the Dojo Toolkit. It lists enterprise app modernization as 30% of its Clutch service mix.

Centric Software's PLM web client was a single-page application of thousands of Dojo Toolkit modules. SitePen built a custom TypeScript and Webpack configuration so new TypeScript modules work next to old Dojo ones, and Centric started shipping React features without a complete rewrite and without interrupting ongoing feature development.

For Marriott, SitePen moved business applications built on Java applets and JSPs to new interfaces that kept the existing business logic. "SitePen's team of experts helped pave the path toward a future of even faster innovation with very timely advice and engineering," said Centric Software's VP of Product Management.

Test score: 3 of 5. Named legacy framework, feature work continued, an interop path. Neither case publishes a number or the length of the engagement.

Honest weakness: SitePen does not disclose its hourly rate, runs a team of 10 to 49 people, and publishes no outcome numbers, so you have to ask for references to size the result.

Best for: enterprise products with a very large Dojo or early JavaScript codebase where interop between old and new code is the hard problem.

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7. Celestial Systems: Ext JS specialists for regulated front ends

Sources: Clutch profile, Financial services case study, Pharma case study

Celestial Systems, founded in 2001, publishes 4 Ext JS cases. Ext JS is also the legacy front end vendors document most often, in 11 of the 31 migration cases.

Celestial rebuilt the main platform of a North American financial services organization from a dated Ext JS framework in React, after earlier providers lacked the Ext JS skills for the move. The team worked inside the client's virtual desktop infrastructure for compliance and grew into a multi-year partnership with zero escalations.

For a Fortune 500 pharma company, Celestial upgraded an eTMF application to Ext JS 7.2 and re-architected it to MVVM. The client got 85% better performance and 80% faster loading.

Test score: 3 of 5. Named legacy framework, published numbers, a multi-year team. Neither case states that the product kept shipping during the move or describes an incremental path.

Honest weakness: at $150 to $199 per hour, Celestial is the most expensive vendor on this list, and it holds only 4 Clutch reviews.

Best for: banks, pharma and other regulated companies running Ext JS that need a vendor fluent in both Ext JS and React.

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8. Code District: Angular to Next.js with a growth number

Sources: Clutch profile, Skywatch case study

Code District, founded in 2017, holds a 4.9 Clutch rating across 35 reviews. Its frontend case publishes the largest user-facing result in this list.

Code District moved Skywatch's satellite imagery portals from Angular 15 to 2 Next.js applications on a shared codebase, with server-side rendering on AWS Lambda@Edge and a white-label layer for enterprise customers. Skywatch reported a 7x increase in monthly active users and 50% fewer development hours, which let both portals get features faster.

The engagement has run since March 2024. "Code District successfully launched our application on time," said Joel Cumming, CTO at Skywatch.

Test score: 3 of 5. Named framework pair, published numbers, an ongoing team. The case describes 2 new applications, so it gives no evidence of an incremental path or of shipping during the move.

Honest weakness: Angular 15 was a supported framework, so this case shows a framework switch with a redesign, and tells you less about rescuing a truly legacy front end.

Best for: product companies whose UI hurts growth and who want a redesign and a move to Next.js in one project.

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9. Rishabh Software: Silverlight to Angular for government workflows

Sources: Clutch profile, Silverlight to Angular case study

Rishabh Software, founded in 1999, is one of the 2 oldest companies on this list. Silverlight appears in 5 of the 31 migration cases in the dataset.

Rishabh moved a UK IT company's information management system for local governments from Silverlight to Angular, keeping the existing business logic, formulas and workflows. The client reported 5x system performance and 30% higher operational efficiency, for cities and counties of 15,000 to 400,000 residents.

The team also moved Crystal reports to SQL Server Reporting Services and added video calling through Twilio.

Test score: 2 of 5. Named framework pair and published numbers. The case gives no timeline, no incremental path, and no detail on how long the team stayed.

Honest weakness: the client is anonymous ("a UK-based IT company") and the case has no dates, so you cannot verify it without asking for a reference.

Best for: public-sector and enterprise software still on Silverlight or other Microsoft client technologies.

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10. ElifTech: AngularJS to React with a team that stayed

Sources: Clutch profile, Feelcapital case study

ElifTech, founded in 2015, has the most Clutch reviews in this list, 60, at a 4.9 rating.

ElifTech moved Feelcapital's investment management platform from AngularJS to React, updated Node.js and the data drivers, and redesigned both the user and admin modules mobile-first. After the migration, Feelcapital kept ElifTech as a dedicated team for maintenance and new features.

Test score: 2 of 5. Named framework pair and a team that stayed. The case publishes no number and no detail on how the product ran during the move.

Honest weakness: the Feelcapital case dates from the Node.js 8 era and publishes no results, so it is old evidence for a 2026 migration.

Best for: fintech startups that want an AngularJS to React move bundled with a redesign at a $25 to $49 hourly rate.

What the data says about frontend migrations

Vendors rarely document the front end. Across 4,097 modernization case studies, 0.8% name the legacy frontend framework that was replaced. The backend gets the detail: databases, clouds and .NET versions.

The legacy front ends that do appear tell you where the hard work is:

Ext JS and Web Forms lead because both carry business logic inside the UI layer. A team that moves them has to pull grids, validation and workflows out of the old framework before React or Angular can take over, which is why the vendors who document these moves also document interop and module-by-module paths. If your front end is jQuery or AngularJS, more vendors can do the work, and the shortlist should turn on signals 2 and 4. For the backend side of the same decision, our guide to moving a legacy app to SaaS covers rebuild versus refactor.

How to choose a frontend modernization partner

Turn the five signals into questions for the first sales call. Each one has an answer you can check.

1. "Which legacy framework did you move off, on which product, and what did you move to?" Ask for the case study and a reference you can call. A vendor that answers with a redesign portfolio fails signal 1.

2. "How many releases did the client ship during the migration?" A good answer names a cadence, such as weekly. Squash Apps and Hotovo publish this kind of answer.

3. "How do old and new code live side by side?" Listen for interop, a strangler pattern, micro-frontends, or module-by-module replacement. SitePen's Dojo and TypeScript interop is the model answer.

4. "What did you measure before and after?" Ask for load time, release frequency, bug escape rate or support tickets. A vendor with no baseline cannot show you the migration worked.

5. "Who maintains the new front end a year later?" A vendor still on the account years later, like UppLabs since 2014 or Valor with TablesReady for 7+ years, built something it could live with.

Two more checks matter for any migration. Ask who owns the component library at the end, and get it written into the contract. Then ask what the vendor needs from your side, such as a product owner for 2 to 6 hours per sprint to approve screens as they move.

If you are choosing between front-end frameworks before you choose a vendor, our React vs Vue comparison covers the trade-offs, and our list of frontend development companies covers teams for new builds.

Cost and pricing

Hourly rates on this list span from $25 to $199, and minimum projects from $10,000 to $25,000, according to the vendors' Clutch profiles in September 2026.

The rate matters less than the length of the migration. Three things drive the total:

• Screen count and logic in the UI. An Ext JS or Web Forms app with validation and workflows inside the screens costs more per screen than a jQuery app with a clean API behind it.
• Parallel running. Shipping features during the migration means running two frameworks for months. It costs more per month and much less in lost revenue than a freeze.
• Test coverage at the start. A front end with no tests needs a test suite before the first screen moves. Squash Apps spent the first 4 weeks of its engagement on CI/CD and tests.

Conclusion

Only 31 of 4,097 published modernization case studies name the legacy front end that was replaced, so the first filter is simple: ask for that case study. Then hold every vendor to The Live Frontend Migration Test: a named framework, a product that kept shipping, an incremental path, a number after the move, and a team that stayed.

If your frontend migration comes with a backend or architecture problem behind it, our application modernization team can review the codebase and give you a plan with the options and their costs.