Replay AI: The Ultimate Solution To Generate Code From Legacy UI Videos

TL;DR: Replay AI reconstructs fully functional, multi-page UIs from video recordings, understanding user behavior and intent far beyond what screenshot-to-code tools can achieve.

Legacy UIs are a black box. Documentation is outdated, developers have moved on, and the only record of functionality is often a dusty screen recording. Trying to reverse-engineer these interfaces is a nightmare of guesswork, manual coding, and endless debugging. But what if you could simply show an AI how the UI is supposed to work and have it generate the code for you? That's the power of Replay.

The Problem: Screenshot-to-Code Falls Short#

The market is flooded with screenshot-to-code tools. They promise instant UI generation, but they all share a fatal flaw: they only understand what pixels are on the screen. They don't understand behavior.

Imagine trying to rebuild an e-commerce checkout flow from screenshots alone. You'd see the "Add to Cart" button, but how does it update the cart total? What happens when a user enters an invalid shipping address? Screenshot-to-code tools can't answer these questions. They generate static images masquerading as interactive components.

Replay: Behavior-Driven Reconstruction#

Replay takes a fundamentally different approach. It analyzes video recordings of user interactions. This "Behavior-Driven Reconstruction" allows Replay to understand not just the visual appearance of the UI, but also the underlying logic and data flow.

Instead of just seeing a button, Replay sees the action associated with the button press. It tracks state changes, API calls, and conditional rendering, building a complete model of the UI's behavior.

This is a game-changer for:

• •Modernizing Legacy Systems: Quickly rebuild outdated UIs without having to decipher spaghetti code.
• •Rapid Prototyping: Demonstrate complex interactions with a simple video recording, then let Replay generate the initial code.
• •Reverse Engineering: Understand how existing applications work by observing user flows.

Key Features That Set Replay Apart#

Replay isn't just another code generation tool. It's a comprehensive platform designed for real-world UI reconstruction.

• •Multi-Page Generation: Replay can analyze videos that span multiple pages and user flows, generating complete applications, not just isolated components.
• •Supabase Integration: Seamlessly connect your generated UI to a Supabase backend for data persistence and authentication.
• •Style Injection: Customize the look and feel of your generated UI by injecting your own CSS or Tailwind styles.
• •Product Flow Maps: Visualize the user flows captured in your video recordings, providing a clear overview of the application's logic.

How Replay Works: A Step-by-Step Guide#

Here's a simplified example of how to use Replay to generate code from a video of a simple to-do list application:

Step 1: Upload Your Video#

Upload a clear video recording of you interacting with the to-do list. Make sure to demonstrate all the key features: adding tasks, marking them as complete, and deleting them.

Step 2: Replay Analyzes the Video#

Replay's AI engine analyzes the video, identifying UI elements, user actions, and data flows. This process can take a few minutes depending on the length of the video.

Step 3: Review and Refine#

Replay presents you with a visual representation of the reconstructed UI, along with the generated code. You can review the code, make adjustments, and add custom logic as needed.

Step 4: Download and Deploy#

Download the generated code as a React component (or other supported framework) and integrate it into your project.

Code Example: Generated To-Do List Component#

Here's an example of the code that Replay might generate for a simple to-do list component:

typescript
import React, { useState } from 'react';

interface Todo {
  id: number;
  text: string;
  completed: boolean;
}

const TodoList = () => {
  const [todos, setTodos] = useState<Todo[]>([
    { id: 1, text: 'Learn Replay AI', completed: false },
    { id: 2, text: 'Build a demo', completed: true },
  ]);

  const [newTodo, setNewTodo] = useState('');

  const handleInputChange = (event: React.ChangeEvent<HTMLInputElement>) => {
    setNewTodo(event.target.value);
  };

  const handleAddTodo = () => {
    if (newTodo.trim() !== '') {
      setTodos([...todos, { id: Date.now(), text: newTodo, completed: false }]);
      setNewTodo('');
    }
  };

  const handleToggleComplete = (id: number) => {
    setTodos(
      todos.map((todo) =>
        todo.id === id ? { ...todo, completed: !todo.completed } : todo
      )
    );
  };

  const handleDeleteTodo = (id: number) => {
    setTodos(todos.filter((todo) => todo.id !== id));
  };

  return (
    <div>
      <h1>To-Do List</h1>
      <input
        type="text"
        value={newTodo}
        onChange={handleInputChange}
        placeholder="Add a new task"
      />
      <button onClick={handleAddTodo}>Add</button>
      <ul>
        {todos.map((todo) => (
          <li key={todo.id}>
            <input
              type="checkbox"
              checked={todo.completed}
              onChange={() => handleToggleComplete(todo.id)}
            />
            <span style={{ textDecoration: todo.completed ? 'line-through' : 'none' }}>
              {todo.text}
            </span>
            <button onClick={() => handleDeleteTodo(todo.id)}>Delete</button>
          </li>
        ))}
      </ul>
    </div>
  );
};

export default TodoList;

This is just a basic example, of course. Replay can handle much more complex UIs, including those with custom styling, API integrations, and state management.

Replay vs. The Competition: A Head-to-Head Comparison#

Here's how Replay stacks up against other code generation tools:

💡 Pro Tip: For best results, record your videos in a well-lit environment with a stable camera. Clear audio can also help Replay understand user actions.

Addressing Common Concerns#

• •Accuracy: Replay's accuracy depends on the quality of the video recording. Clear, well-lit videos with minimal background noise will produce the best results.
• •Complexity: Replay can handle complex UIs, but extremely intricate or poorly designed interfaces may require manual adjustments to the generated code.
• •Security: Replay does not store or transmit sensitive data from your video recordings. All analysis is performed securely and privately.

The Future of UI Development#

Replay is more than just a code generation tool; it's a glimpse into the future of UI development. By leveraging the power of AI to understand user behavior, Replay is democratizing access to modern UI technologies and empowering developers to build better applications faster.

⚠️ Warning: Replay is a powerful tool, but it's not a replacement for skilled developers. You'll still need to understand the fundamentals of UI development and be able to customize and extend the generated code.

📝 Note: Replay supports a variety of UI frameworks and libraries, including React, Vue.js, and Angular. We are constantly adding support for new technologies.

Frequently Asked Questions#

Is Replay free to use?#

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

How is Replay different from v0.dev?#

While v0.dev focuses on generating UI components from text prompts, Replay reconstructs entire applications from video recordings, understanding user behavior and data flows. Replay excels at reverse-engineering existing UIs and capturing complex interactions.

What kind of videos work best with Replay?#

Videos with clear, stable footage of the UI being interacted with work best. Avoid shaky cameras, poor lighting, and excessive background noise. A clear voiceover explaining the interaction can also improve accuracy.

What frameworks and libraries are supported?#

Currently, Replay primarily supports React, but we are actively working on expanding support for other popular frameworks like Vue.js and Angular. It can also generate code compatible with Tailwind CSS and Material UI.

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