How to Rebuild a Complete Web App from Video to Code with Replay: A Complete 2026 Guide

TL;DR: Rebuild entire web applications from screen recordings using Replay's behavior-driven reconstruction, going beyond simple screenshot-to-code conversion.

The dream of automatically generating code from visual inputs has been around for years. Screenshot-to-code tools offer a partial solution, but they often fall short when dealing with dynamic user interactions and multi-page applications. They capture the appearance but miss the intent.

Replay changes the game. Instead of relying on static images, Replay analyzes video recordings of user flows, leveraging Gemini to understand user behavior and reconstruct fully functional UI components and applications. This "behavior-driven reconstruction" unlocks a new level of automation, letting you rebuild complex web apps from simple screen recordings.

Why Video-to-Code is the Future#

Traditional screenshot-to-code solutions treat the UI as a static entity. They can generate code representing the visual layout, but they struggle to capture dynamic behavior, state changes, and multi-page workflows.

Here's how Replay differs:

Replay's video-to-code approach allows for:

• •Complete application reconstruction: Generate code for entire user flows, not just individual pages.
• •Behavior-driven code: Code reflects the intent behind user actions, not just visual appearance.
• •Faster prototyping: Quickly create functional prototypes from user recordings.
• •Reduced development time: Automate the process of rebuilding existing applications.

Rebuilding a Web App with Replay: A Step-by-Step Guide#

Let's walk through the process of rebuilding a web application from a video recording using Replay. This example will demonstrate how to reconstruct a simple to-do list application.

Step 1: Capture the User Flow#

First, record a video of yourself interacting with the to-do list application. This video should demonstrate all the key functionalities:

• •Adding a new task
• •Marking a task as complete
• •Deleting a task

💡 Pro Tip: Ensure the video is clear and stable. Speak clearly while interacting with the app to provide additional context for Replay.

Step 2: Upload the Video to Replay#

Navigate to the Replay platform and upload the video recording. Replay will automatically process the video and begin analyzing the user behavior.

Step 3: Review the Generated Code#

Replay will generate code based on its analysis of the video. This code will include:

• •UI components: React components for the to-do list, input field, and buttons.
• •State management: Code to manage the list of tasks and their completion status.
• •Event handlers: Functions to handle user interactions, such as adding, completing, and deleting tasks.

Here's an example of the generated React component for adding a new task:

typescript
// Generated by Replay
import React, { useState } from 'react';

const AddTask = ({ onAddTask }: { onAddTask: (task: string) => void }) => {
  const [newTask, setNewTask] = useState('');

  const handleSubmit = (e: React.FormEvent) => {
    e.preventDefault();
    if (newTask.trim() !== '') {
      onAddTask(newTask);
      setNewTask('');
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <input
        type="text"
        placeholder="Add new task"
        value={newTask}
        onChange={(e) => setNewTask(e.target.value)}
      />
      <button type="submit">Add</button>
    </form>
  );
};

export default AddTask;

Step 4: Refine and Customize the Code#

While Replay aims for accuracy, you may need to refine and customize the generated code. This could involve:

• •Adjusting styles: Fine-tuning the CSS to match the original application's appearance.
• •Adding missing functionality: Implementing any features that were not captured in the video.
• •Optimizing performance: Improving the code's efficiency and scalability.

Replay supports style injection, allowing you to easily apply custom CSS to the generated components.

Step 5: Integrate with Backend (Optional)#

If your application requires a backend, you can integrate the generated code with your existing API or database. Replay offers seamless integration with Supabase, allowing you to quickly connect your UI to a scalable backend.

📝 Note: Replay intelligently infers data models and API interactions from the video, significantly simplifying the backend integration process.

Step 6: Deploy and Test#

Once you've refined and customized the code, deploy the application to your chosen hosting platform. Thoroughly test the application to ensure that all functionalities are working as expected.

Replay's Key Features: Beyond Simple Code Generation#

Replay offers several key features that distinguish it from traditional code generation tools:

• •Multi-page generation: Reconstruct entire multi-page applications from a single video recording.
• •Supabase integration: Seamlessly connect your UI to a scalable backend with Supabase.
• •Style injection: Easily customize the appearance of the generated components with custom CSS.
• •Product Flow maps: Visualize the user flow captured in the video, providing a clear overview of the application's functionality.

These features empower developers to:

• •Accelerate development: Drastically reduce the time required to rebuild existing applications.
• •Improve collaboration: Share video recordings with designers and developers to facilitate communication and understanding.
• •Reduce errors: Minimize the risk of introducing errors during the manual coding process.

Example: Generating a Complete To-Do List App#

Let's look at a more complete example of the code generated by Replay for a simple to-do list application.

First, the main

component:

typescript
// Generated by Replay
import React, { useState, useEffect } from 'react';
import AddTask from './AddTask';
import TaskList from './TaskList';

const App = () => {
  const [tasks, setTasks] = useState<string[]>([]);

  useEffect(() => {
    // Load tasks from local storage or an API (inferred from video)
    const storedTasks = localStorage.getItem('tasks');
    if (storedTasks) {
      setTasks(JSON.parse(storedTasks));
    }
  }, []);

  useEffect(() => {
    // Save tasks to local storage
    localStorage.setItem('tasks', JSON.stringify(tasks));
  }, [tasks]);

  const handleAddTask = (task: string) => {
    setTasks([...tasks, task]);
  };

  const handleDeleteTask = (index: number) => {
    const newTasks = [...tasks];
    newTasks.splice(index, 1);
    setTasks(newTasks);
  };

  return (
    <div className="container">
      <h1>To-Do List</h1>
      <AddTask onAddTask={handleAddTask} />
      <TaskList tasks={tasks} onDeleteTask={handleDeleteTask} />
    </div>
  );
};

export default App;

And the

component:

typescript
// Generated by Replay
import React from 'react';

const TaskList = ({ tasks, onDeleteTask }: { tasks: string[]; onDeleteTask: (index: number) => void }) => {
  return (
    <ul>
      {tasks.map((task, index) => (
        <li key={index}>
          {task}
          <button onClick={() => onDeleteTask(index)}>Delete</button>
        </li>
      ))}
    </ul>
  );
};

export default TaskList;

This code provides a fully functional to-do list application, complete with state management, event handling, and UI components. Replay inferred the local storage persistence from the video, demonstrating its ability to understand complex application behavior.

⚠️ Warning: While Replay significantly accelerates the development process, always review and test the generated code thoroughly. Human oversight is crucial for ensuring code quality and security.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited features. Paid plans are available for more advanced functionality and higher usage limits.

How is Replay different from v0.dev?#

While both tools aim to generate code, Replay analyzes video recordings to understand user behavior, while v0.dev primarily relies on text prompts and pre-defined templates. Replay's video-to-code approach allows for more accurate and comprehensive application reconstruction. Replay focuses on understanding the intent behind the UI, not just the visual appearance.

What kind of applications can I rebuild with Replay?#

Replay is suitable for rebuilding a wide range of web applications, including e-commerce sites, dashboards, and productivity tools. The key requirement is a clear video recording of the user interacting with the application.

Does Replay support different UI frameworks?#

Currently, Replay primarily focuses on generating React code. Support for other frameworks, such as Vue.js and Angular, is planned for future releases.

How accurate is the generated code?#

Replay's accuracy is constantly improving as the underlying Gemini model evolves. However, it's important to review and test the generated code thoroughly to ensure that it meets your requirements.

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