Replay vs. v0.dev for State Management: Which AI Generates Better Redux Code from Video? (2026)

TL;DR: Replay's behavior-driven reconstruction, leveraging video input and Gemini, generates more accurate and maintainable Redux code compared to v0.dev, particularly when complex state management and multi-page workflows are involved.

Replay vs. v0.dev for State Management: Which AI Generates Better Redux Code from Video? (2026)#

The promise of AI-powered code generation is finally materializing, offering developers the potential to drastically reduce development time and focus on higher-level logic. However, the quality and maintainability of the generated code vary significantly between tools. Two prominent players in this space are Replay and v0.dev, both aiming to automate UI creation. But how do they fare when it comes to generating robust state management code, specifically using Redux? This article dives deep into a practical comparison, focusing on Redux code generation from video input.

The Core Difference: Behavior vs. Appearance#

The fundamental difference lies in their approach. v0.dev, like many AI code generators, primarily analyzes visual elements. It identifies UI components and attempts to recreate them based on appearance. Replay, on the other hand, employs "Behavior-Driven Reconstruction." It analyzes video of user interactions, understanding the intent behind those actions and generating code that reflects the underlying logic. This is crucial for accurate state management.

The Challenge: Recreating a Multi-Step Product Checkout Flow with Redux#

To illustrate the difference, let's consider a common scenario: a multi-step product checkout flow. This involves multiple pages, form submissions, data fetching, and complex state updates. Successfully generating Redux code for this requires understanding the flow of data and user actions across different pages.

v0.dev's Approach: Visual Reconstruction Limitations

v0.dev, primarily focused on visual reconstruction, often struggles with complex state management in multi-page applications. It might generate visually appealing components, but the underlying Redux implementation can be incomplete or inaccurate. For example, when presented with a video of a user adding items to a cart across multiple product pages, v0.dev might generate individual components for each page but fail to correctly manage the cart state across these pages.

Replay's Approach: Behavior-Driven Redux

Replay excels in this scenario because it analyzes the video to understand the behavior of the user: the actions they take, the data they enter, and how the UI responds. This allows Replay to generate Redux code that accurately reflects the application's state transitions.

A Practical Example: Generating Redux for a Shopping Cart#

Let's say we have a video of a user adding a product to a shopping cart. Here's how Replay might generate the corresponding Redux reducer:

typescript
// Replay generated Redux reducer
const initialState = {
  cartItems: [],
  total: 0,
};

const cartReducer = (state = initialState, action) => {
  switch (action.type) {
    case 'ADD_TO_CART':
      const newItem = action.payload;
      const existingItem = state.cartItems.find(item => item.id === newItem.id);

      if (existingItem) {
        return {
          ...state,
          cartItems: state.cartItems.map(item =>
            item.id === newItem.id ? { ...item, quantity: item.quantity + 1 } : item
          ),
        };
      } else {
        return {
          ...state,
          cartItems: [...state.cartItems, { ...newItem, quantity: 1 }],
        };
      }
    case 'REMOVE_FROM_CART':
      return {
        ...state,
        cartItems: state.cartItems.filter(item => item.id !== action.payload),
      };
    case 'UPDATE_QUANTITY':
      return {
        ...state,
        cartItems: state.cartItems.map(item =>
          item.id === action.payload.id ? { ...item, quantity: action.payload.quantity } : item
        ),
      };
    default:
      return state;
  }
};

export default cartReducer;

This code, generated directly from a video of user interaction, accurately manages the cart state, including adding items, removing items, and updating quantities. Replay infers the necessary actions and state updates from the video, resulting in functional and maintainable Redux code.

Step-by-Step Guide: Using Replay for Redux Code Generation#

Here's a simplified example of using Replay to generate Redux code for a simple counter application:

Step 1: Record the User Interaction#

Record a video of yourself interacting with a basic counter UI (increment, decrement, reset). Ensure the video clearly shows the actions and the resulting changes in the UI.

Step 2: Upload to Replay#

Upload the video to Replay. The engine will analyze the video and identify the user interactions and state changes.

Step 3: Review and Refine#

Replay will generate the Redux code, including actions, reducers, and potentially even selectors. Review the generated code and make any necessary refinements.

typescript
// Example Redux reducer generated by Replay
const counterReducer = (state = 0, action) => {
  switch (action.type) {
    case 'INCREMENT':
      return state + 1;
    case 'DECREMENT':
      return state - 1;
    case 'RESET':
      return 0;
    default:
      return state;
  }
};

export default counterReducer;

Step 4: Integrate into Your Application#

Integrate the generated Redux code into your application.

💡 Pro Tip: For more complex applications, break down the video into smaller, more focused segments. This can improve the accuracy of the generated code.

The Importance of Supabase Integration#

Replay's native Supabase integration further enhances its ability to handle complex state management. When the video includes interactions with a Supabase database (e.g., fetching product data, updating user profiles), Replay can automatically generate the necessary Redux actions and reducers to manage the data flow between the UI and the database.

📝 Note: While both tools may offer integrations with backend services, Replay's deep understanding of user behavior allows for more seamless and accurate integration.

Style Injection for a Polished UI#

Beyond state management, Replay also excels at style injection. It analyzes the visual elements in the video and generates CSS or Tailwind CSS code to match the UI's appearance. This ensures that the generated code not only functions correctly but also looks visually appealing.

Product Flow Maps: Visualizing the Application's Logic#

Replay's "Product Flow maps" provide a visual representation of the application's logic, derived directly from the video. This helps developers understand the flow of data and user interactions, making it easier to maintain and extend the generated code.

⚠️ Warning: While AI code generation tools can significantly accelerate development, it's crucial to review and test the generated code thoroughly. Always treat AI-generated code as a starting point, not a finished product.

Key Advantages of Replay:#

• •Accurate Redux Generation: Behavior-driven analysis leads to more accurate and maintainable Redux code.
• •Multi-Page Support: Handles complex state management across multiple pages with ease.
• •Supabase Integration: Seamless integration with Supabase for managing data flow.
• •Style Injection: Generates CSS or Tailwind CSS code to match the UI's appearance.
• •Product Flow Maps: Provides a visual representation of the application's logic.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited usage. Paid plans are available for higher usage and access to advanced features.

How is Replay different from v0.dev?#

Replay analyzes video of user interactions to understand behavior and generate code, while v0.dev primarily focuses on visual reconstruction from text prompts or screenshots. Replay's behavior-driven approach leads to more accurate and maintainable code, especially for complex state management and multi-page applications.

Can Replay generate code for other state management libraries besides Redux?#

Currently, Replay is optimized for Redux. Support for other state management libraries is planned for future releases.

---

Ready to try behavior-driven code generation? Get started with Replay - transform any video into working code in seconds.