How to Reconstruct a Complete Next.js App from Video with Replay in 2026: A Detailed Tutorial

TL;DR: Reconstruct a fully functional Next.js application from a video recording of user interactions using Replay's behavior-driven reconstruction engine, leveraging its multi-page generation, Supabase integration, and style injection capabilities.

The dream of automatically generating code from visual input is no longer science fiction. Traditional screenshot-to-code tools are limited because they only understand the appearance of a UI, not the behavior behind it. That's where Replay steps in, revolutionizing the development workflow by analyzing video recordings to reconstruct working UI with a deep understanding of user intent. This tutorial will guide you through reconstructing a complete Next.js application from a video using Replay in 2026, showcasing its advanced features and practical implementation.

Understanding Behavior-Driven Reconstruction#

Replay uses a "Behavior-Driven Reconstruction" approach. It's a game-changer because it treats video as the source of truth. This means Replay doesn't just see pixels; it understands what a user is trying to achieve. This is crucial for generating code that's not only visually accurate but also functionally correct.

Think about it: a button isn't just a rectangle with text. It's an interactive element that triggers an action. Replay understands this action based on the video, allowing it to generate the appropriate event handlers and logic.

Key Features of Replay#

Replay offers a suite of features that make video-to-code reconstruction a seamless and powerful process:

• •Multi-page Generation: Replay can analyze videos that demonstrate navigation between multiple pages and reconstruct the entire application structure, including routing and state management.
• •Supabase Integration: Seamlessly integrate with Supabase for backend functionality, including authentication, database interactions, and real-time updates.
• •Style Injection: Replay intelligently infers and applies styling based on the video, ensuring the reconstructed UI matches the original design.
• •Product Flow Maps: Visualize the user journey captured in the video, providing a clear understanding of the application's flow and interactions.

Let's compare Replay to other code generation tools:

Tutorial: Reconstructing a Next.js App from Video#

Let's dive into a step-by-step guide on how to reconstruct a Next.js application from a video using Replay. Imagine you have a video recording of a user interacting with a prototype of a task management application. This video showcases user registration, task creation, task editing, and task completion.

Step 1: Prepare the Video#

Ensure the video is clear and captures all relevant user interactions. A high-resolution recording with minimal distractions is ideal. The video should clearly demonstrate the user flow, including navigation between pages, form submissions, and interactions with UI elements.

💡 Pro Tip: Record the video in a well-lit environment and use a screen recording tool that captures mouse movements and clicks. This will help Replay accurately analyze user behavior.

Step 2: Upload the Video to Replay#

Navigate to the Replay platform and upload the video file. Replay supports various video formats, including MP4, MOV, and WebM. Once uploaded, Replay will begin analyzing the video, identifying UI elements, user interactions, and application flow.

Step 3: Configure Project Settings#

Configure project settings to specify the target framework (Next.js), desired styling approach (CSS Modules, Styled Components, Tailwind CSS), and Supabase integration details (if applicable).

📝 Note: Replay automatically detects the technologies used in the video, but you can manually adjust these settings to fine-tune the reconstruction process.

Step 4: Initiate Reconstruction#

Initiate the reconstruction process. Replay will analyze the video frame by frame, identifying UI elements, user interactions, and application flow. This process may take several minutes, depending on the length and complexity of the video.

Step 5: Review and Refine the Generated Code#

Once the reconstruction is complete, Replay will present a preview of the generated Next.js application. Review the code and make any necessary adjustments. Replay provides a code editor that allows you to directly modify the generated code.

⚠️ Warning: While Replay strives for pixel-perfect accuracy, minor adjustments may be necessary to ensure the reconstructed application meets your specific requirements.

Step 6: Integrate with Supabase (Optional)#

If the video demonstrates interactions with a backend (e.g., user authentication, data fetching), Replay will automatically generate Supabase integration code. Review and configure the Supabase integration to connect the reconstructed application to your Supabase project.

typescript
// Example of Supabase integration code generated by Replay
import { createClient } from '@supabase/supabase-js';

const supabaseUrl = process.env.NEXT_PUBLIC_SUPABASE_URL;
const supabaseKey = process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY;

export const supabase = createClient(supabaseUrl, supabaseKey);

export const fetchTasks = async (userId: string) => {
  const { data, error } = await supabase
    .from('tasks')
    .select('*')
    .eq('user_id', userId);

  if (error) {
    console.error('Error fetching tasks:', error);
    return [];
  }

  return data;
};

Step 7: Download and Deploy#

Download the generated Next.js project and deploy it to your preferred hosting platform (e.g., Vercel, Netlify). The downloaded project will include all necessary files, including components, pages, API routes, and styling.

Advanced Techniques and Customization#

Replay offers several advanced techniques and customization options to further enhance the reconstruction process:

• •Style Injection Customization: Fine-tune the style injection process by providing custom CSS or theme files. This allows you to ensure the reconstructed application matches your brand's visual identity.
• •Behavior Mapping: Manually map user interactions to specific code actions. This is useful for complex interactions that Replay may not automatically detect.
• •Component Libraries: Integrate with existing component libraries (e.g., Material UI, Ant Design) to leverage pre-built UI components and accelerate development.

Benefits of Using Replay#

• •Accelerated Development: Reconstruct UIs from video in minutes, saving countless hours of manual coding.
• •Improved Accuracy: Behavior-driven reconstruction ensures the generated code is both visually accurate and functionally correct.
• •Enhanced Collaboration: Share video recordings and reconstructed code with team members for seamless collaboration.
• •Reduced Costs: Automate the UI development process and reduce reliance on manual coding.

Example: Reconstructed Task Component#

Here's an example of a Task component that Replay might generate from the video:

typescript
// Example of a Task component generated by Replay
import { useState } from 'react';

interface TaskProps {
  id: string;
  title: string;
  completed: boolean;
  onUpdate: (id: string, completed: boolean) => void;
  onDelete: (id: string) => void;
}

const Task: React.FC<TaskProps> = ({ id, title, completed, onUpdate, onDelete }) => {
  const [isCompleted, setIsCompleted] = useState(completed);

  const handleCheckboxChange = () => {
    setIsCompleted(!isCompleted);
    onUpdate(id, !isCompleted);
  };

  return (
    <div className="task">
      <input
        type="checkbox"
        checked={isCompleted}
        onChange={handleCheckboxChange}
      />
      <span>{title}</span>
      <button onClick={() => onDelete(id)}>Delete</button>
    </div>
  );
};

export default Task;

This component includes state management, event handlers, and styling, all automatically generated by Replay based on the video recording.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited functionality and paid plans for more advanced features and usage. Check the pricing page for the most up-to-date information.

How is Replay different from v0.dev?#

While both tools aim to generate code, Replay distinguishes itself by using video as input and focusing on behavior-driven reconstruction. v0.dev primarily uses text prompts and generates code based on the desired UI appearance. Replay understands the intent behind user interactions, leading to more accurate and functional code generation.

What types of applications can Replay reconstruct?#

Replay can reconstruct a wide range of applications, including web applications, mobile applications, and desktop applications. The key requirement is a clear video recording of user interactions with the application.

What level of technical expertise is required to use Replay?#

While a basic understanding of web development concepts is helpful, Replay is designed to be user-friendly and accessible to developers of all skill levels. The platform provides clear instructions and helpful documentation to guide you through the reconstruction process.

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