Design the whole workflow
Build an upload screen, a review queue, and a detail page with their own URLs. Connect them through Python state and event handlers, then persist business records in your database.
Your Gradio demo proved the model. Build the product with Reflex.
Keep the Python you already wrote. Build the pages, review workflows, and custom interface your users need around it. Reflex brings your application UI and backend logic together in Python, with a React frontend and your choice of hosting.
Build the application around your model
Your model is only one part of the product. Give users a place to submit work, review results, make decisions, and come back to their records. Reflex brings those screens and interactions into one Python application.
Make the interface your own
Style individual components with CSS-like props, CSS, or Tailwind. Compose your own layouts and wrap React components when your product needs a specialized interaction.
Connect identity to the work
Integrate authentication and enforce permissions in backend handlers. Give reviewers, operators, and administrators the right actions and records for their role.
Keep your Python investment
Call your model, preprocessing code, and existing services from Reflex handlers. Keep inference infrastructure separate when it needs its own hardware, queue, or scaling policy.
Choose where the app runs
Use managed Reflex hosting or self-host the frontend and Python backend in your cloud or on premises. Choose deployment around your data and operating requirements.
Gradio vs. Reflex, side by side
Both start from Python. Compare how you build the application around it.
Scroll horizontally to compare both products.
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| Decision | Gradio | Reflex |
|---|---|---|
| Built for | Python interfaces for models, APIs, and functions, from demos to interactive applications. | Full-stack applications with a custom interface, Python state, and server-side event handlers. |
| Pages | Multipage apps with URL routes through Blocks.route(), as well as tabs and layouts. | Static and dynamic routes, with page components and application navigation authored in Python. |
| State | Global, per-session, and browser state; durable records need a persistence layer. | Typed Python State classes and event handlers, with per-session state shared across views. Persist durable records in a database. |
| Authentication | Built-in login supports credentials or a callable; FastAPI integration supports external authentication. | Integrate authentication and implement backend authorization checks. Reflex Enterprise also offers an OIDC plugin with separate terms and configuration. |
| UI customization | Themes, custom CSS and JavaScript, layouts, and custom components. | Built-in components, CSS-like style props, Tailwind, and wrappers for React libraries to build your own application design. |
| Existing backend | Call Python functions or services; mount a Gradio app within FastAPI. | Reuse independent Python logic and call existing APIs from event handlers. Adapt authentication, data contracts, and error handling as needed. |
| Deployment | Self-host on your own infrastructure or use a hosting service such as Hugging Face Spaces. | Managed Reflex hosting or self-hosting in your cloud or on premises, with control over the frontend and Python backend. |
| Code and license | Your application code, using an Apache 2.0 open-source framework. | Your Python application source and generated frontend, using an Apache 2.0 open-source framework. Managed products have separate terms. |
Build sliders, uploads, chat interfaces, and streaming responses into the surrounding workflow. Specialized audio, image, or model interactions may need a wrapped component or custom integration. Check the components and behavior your current Gradio app relies on as part of the migration.
Explore Reflex componentsStarting a new project instead of migrating one?
Build the product you have in mind from the first page.
Start with Reflex when the goal is a complete application around your model: a branded interface, connected pages, business records, and actions for different users. Your Python team can build the interface and backend logic together without maintaining a separate handwritten React app.
Define the workflow and state model from the start, then add screens as the product grows. Choose managed hosting or your own infrastructure when you are ready to deploy. Production readiness still includes access controls, persistence, monitoring, and testing with your expected traffic.
What actually moves when you switch
Keep the model and the independent Python code you trust. Rebuild the interface and interaction layer one workflow at a time, validating the result against the app your users already know.
01
Reuse your Python logic
Separate model calls, preprocessing, and business rules from Gradio-specific inputs and outputs. Reuse those functions or call the same inference endpoint, adapting data contracts where needed.
02
Rebuild the interface
Replace Interface or Blocks layouts with Reflex components. Map inputs, uploads, streaming output, and error states to the experience you want users to have.
03
Map state and events
Move interaction state into typed Reflex State classes and event handlers. Share the appropriate session data across pages, and store durable records in your database.
04
Deploy and validate
Connect your existing backend and identity provider, then deploy with Reflex hosting or your own infrastructure. Test inference outputs, permissions, failures, concurrency, and recovery before switching users.
What teams have built with Reflex
Examples from teams building with Reflex. These are customer-reported results from a Streamlit migration and a React/FastAPI comparison; they are not Gradio migration benchmarks.
8-9 hours
World Bank · Streamlit migration
A World Bank engineer reported converting a Streamlit app with Reflex Build in eight to nine hours. The team's existing Python services remained part of the application.
Read the customer story10x faster
SellerX · Compared with React and FastAPI
SellerX reported developing with Reflex ten times faster than with React and FastAPI. The result describes that team's experience, not an average across projects.
Read the customer storyQuestions people ask before choosing
Production, customization, and moving your existing application.
Should I start with Gradio or Reflex for a new project?
Choose Reflex when your goal is a complete product around a model, with a custom interface, connected workflows, and business records. You can author the UI and backend logic in Python and extend the frontend with React components when needed.
Is Gradio ready for production?
Gradio can be deployed in production and supports multipage apps, state, and authentication integrations. Readiness depends on the application and its hosting, security, and operational setup. Reflex offers a different foundation for teams that want to organize the whole product around Python components, state, and event handlers.
What are Gradio's limitations?
The question is how well its Interface and Blocks model fits your product. Gradio supports routes, session state, custom CSS, and external authentication, but complex business workflows still require application architecture, persistence, and authorization. Reflex makes custom pages and Python state classes the foundation for that work.
Can you fully customize a Gradio app's UI?
Gradio supports themes, custom CSS and JavaScript, and custom components. Reflex offers a component-based approach with CSS-like style props, Tailwind classes, and React component wrappers. Choose Reflex when you want to compose the application around your own design and workflows.
Does Gradio scale?
Gradio provides queueing and concurrency controls, but capacity also depends on model serving, hardware, session handling, and deployment. Moving the UI to Reflex does not automatically make inference faster. Keep expensive model work independently scalable and load-test the full application.
What is a good Python alternative to Gradio for a production app?
Reflex is a strong alternative when you want a full application around your model. Author pages, state, and server-side handlers in Python, use the generated React frontend, and connect the existing services and data your product depends on.
Can Reflex do everything Gradio can?
Reflex supports common application interactions such as uploads, sliders, chat interfaces, and streaming updates. It is not a drop-in replacement for every Gradio component or API. Specialized media inputs and model interactions may need custom integration or a wrapped React component.
How long does it take to migrate from Gradio to Reflex?
Estimate from the screens, event wiring, state, and integrations you need to rebuild. Start with one representative workflow and measure the work before planning a rollout. The World Bank's eight-to-nine-hour result was a Streamlit migration using Reflex Build, not a Gradio estimate.
Can I keep my existing backend?
Yes. You can call existing APIs or reuse independent Python functions from Reflex event handlers. Keep model serving where it already runs when that makes sense. Check request and response formats, authentication, streaming, and failure handling rather than assuming every integration transfers unchanged.
Start the move
Install Reflex and rebuild your first page today. Bring the model, data, and Python logic your application already depends on.