Learn how to successfully migrate a Flutter mobile healthcare app to web, including solutions for CORS authentication, performance optimization, and responsive design challenges. This case study demonstrates reusing 70-80% of mobile codebase while delivering consistent cross-platform user experiences.
We took a Flutter app from mobile to the web to build a robust multi-platform experience for a healthcare client.
The goal was simple: build a fast, intuitive, and reliable app that worked across iOS and Android using a single codebase – a core principle of application modernization that ensures scalability and long-term agility. Flutter didn’t just deliver—it impressed. But as with many digital transformation and digital healthcare solutions journeys, the next logical question was, “Can we use the same codebase to create a seamless web experience, too?”. That question kicked off a new phase in the Brillio journey—one filled with challenges, trade-offs, and healthy learning.
With users ranging from young adults to senior citizens, UI consistency and performance were key. In fact, research shows that in the U.S. over 60% of patients are using mobile health applications or digital health tools to manage their health — underscoring the need for web accessibility and responsive design in digital healthcare solutions. Keeping all this in mind, Flutter offered the following:
The above benefits meant our team had to contend with fewer moving parts. We were given a unique opportunity to deliver rapid value without scaling multiple teams for each platform. However, the journey to building the Flutter web app experience came with its own set of surprises. It wasn’t a mere copy-paste of the mobile experience into a browser. Instead, it required a new way of thinking encompassing design, performance, and architecture.
The challenge? CORS.
Cross-origin Resource Sharing (CORS) isn’t something one deals with much in native mobile apps. But in a browser environment, it’s front and center. We had to work closely with the client’s identity management team to ensure that all the right domains were whitelisted and that token flows worked correctly across different environments. We realized that baking the CORS integration into planning early while moving to the web avoids late-stage surprises when using federated authentication like OKTA.
Load times were longer than a typical React-based web app, especially on slower networks. We addressed this by optimizing asset sizes, lazy-loading screens where possible, and being conscious of third-party libraries. We also ran into some layout quirks that appeared only in certain browsers, which meant more testing and edge-case handling. If ever, a client wishes to convert a Flutter app to web, we suggest budgeting time for performance profiling and browser-specific QA.
Here are a few tips:
The client was able to:
For us, it also validated Flutter as a viable framework for multi-platform delivery in regulated industries like healthcare. Flutter is a powerful cross-platform tool that, when used strategically, can speed up development, lower costs, and improve overall quality. That said, it has challenges—especially when transitioning from mobile to web. For us, the journey has been well worth it. We’ve delivered more value to our healthcare client, reduced tech debt, and created a foundation that can evolve with their needs. As an digital transformation services and experience enabler, telling our clients, “Yes, we can build that once and take it to multiple platforms,” is a game-changer. After all, isn’t that what modern software delivery is all about?
