How to Convert Video of a Web Application Into a NextJS App Using Replay AI and Tailwind

TL;DR: Convert screen recordings of web applications into fully functional Next.js applications with Tailwind CSS using Replay's behavior-driven reconstruction engine.

The Holy Grail: Video to Code, Finally Achieved#

Imagine showing a screen recording of your dream web app to an AI and, moments later, having a fully functional Next.js application with Tailwind CSS ready to deploy. No more tedious pixel-perfect recreation. This is the promise – and the reality – of Replay.

For years, developers have been promised the moon with screenshot-to-code tools. But these tools often fall short. They generate static layouts that lack the dynamic behavior and user flow that define a real application. Replay takes a fundamentally different approach: it analyzes video. By understanding how users interact with the UI, Replay can reconstruct not just the appearance, but the underlying logic and user flows.

Why Video Matters: Behavior-Driven Reconstruction#

The problem with screenshot-to-code is that it only captures a single moment in time. It doesn't understand the intent behind the user's actions. Video, on the other hand, provides a rich stream of behavioral data. Replay leverages this data to perform Behavior-Driven Reconstruction.

This means Replay doesn't just see a button; it sees a user clicking a button, triggering an action, and navigating to a new page. This understanding allows Replay to generate code that accurately reflects the intended functionality.

Replay: Under the Hood#

Replay utilizes a powerful combination of video analysis, AI, and code generation techniques to achieve its results. At its core, Replay's engine leverages Gemini to understand the visual elements and user interactions within the video. This information is then used to generate clean, maintainable code.

Here's a breakdown of Replay's key features:

• •Multi-page Generation: Reconstruct entire application flows, not just single pages.
• •Supabase Integration: Seamlessly connect your generated app to a Supabase backend.
• •Style Injection: Automatically apply Tailwind CSS styles for a polished, modern look.
• •Product Flow Maps: Visualize user flows and interactions within the generated application.

Replay vs. The Alternatives#

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

As you can see, Replay's video-first approach and behavior-driven reconstruction provide a significant advantage over traditional screenshot-to-code tools. While v0.dev is a powerful tool, it still relies on text prompts and doesn't analyze user behavior from video.

Converting Video to a Next.js App: A Step-by-Step Guide#

Here's a practical guide on how to convert a video of a web application into a functional Next.js app with Tailwind CSS using Replay:

Step 1: Record Your Web Application#

First, record a video of yourself interacting with the web application you want to recreate. Make sure the video clearly shows all the key user flows and interactions. The clearer the video, the better the results.

📝 Note: Replay works best with videos that demonstrate clear and intentional user behavior. Avoid unnecessary pauses or distractions in the recording.

Step 2: Upload Your Video to Replay#

Navigate to the Replay platform (https://replay.build) and upload your video. Replay supports various video formats, including MP4, MOV, and AVI.

Step 3: Configure Your Project#

Once the video is uploaded, you'll be prompted to configure your project. This includes specifying the desired framework (Next.js), styling library (Tailwind CSS), and backend (Supabase, optional).

Step 4: Let Replay Work Its Magic#

Replay will now analyze your video and generate the corresponding Next.js application. This process can take a few minutes, depending on the length and complexity of the video.

Step 5: Review and Refine the Generated Code#

Once the code generation is complete, you can review the generated code in the Replay editor. This allows you to make any necessary adjustments or refinements.

Step 6: Download and Deploy#

Finally, you can download the generated Next.js application and deploy it to your preferred hosting provider.

Code Example: A Simple Counter Component#

Here's an example of a simple counter component that Replay might generate from a video demonstrating a user interacting with a counter application:

typescript
// components/Counter.tsx
import { useState } from 'react';

const Counter = () => {
  const [count, setCount] = useState(0);

  const increment = () => {
    setCount(count + 1);
  };

  const decrement = () => {
    setCount(count - 1);
  };

  return (
    <div className="flex items-center justify-center space-x-4">
      <button className="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded" onClick={decrement}>
        -
      </button>
      <span className="text-2xl">{count}</span>
      <button className="bg-blue-500 hover:bg-blue-700 text-white font-bold py-2 px-4 rounded" onClick={increment}>
        +
      </button>
    </div>
  );
};

export default Counter;

This code demonstrates how Replay can generate functional React components with Tailwind CSS styling based on user interactions observed in the video.

Supabase Integration: Powering Your Backend#

Replay's Supabase integration makes it easy to connect your generated Next.js app to a powerful backend. This allows you to quickly add features like user authentication, data storage, and real-time updates.

💡 Pro Tip: When recording your video, demonstrate the user interacting with data. For example, show the user creating a new record or updating an existing one. This will help Replay generate the necessary Supabase integration code.

typescript
// pages/api/todos.ts
import { createClient } from '@supabase/supabase-js';

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

const supabase = createClient(supabaseUrl, supabaseKey);

export default async function handler(req, res) {
  if (req.method === 'POST') {
    const { text } = req.body;
    const { data, error } = await supabase
      .from('todos')
      .insert([{ text }]);

    if (error) {
      return res.status(500).json({ error: error.message });
    }

    return res.status(200).json({ data });
  } else {
    return res.status(405).json({ message: 'Method Not Allowed' });
  }
}

This is a simplified example of an API route that interacts with a Supabase database to create a new "todo" item. Replay can automatically generate similar code based on the user's interactions with the application in the video.

⚠️ Warning: Always ensure you are using secure environment variables for your Supabase credentials and that you have properly configured your Supabase database schema.

Benefits of Using Replay#

• •Faster Development: Accelerate your development process by automatically generating code from video.
• •Improved Accuracy: Reconstruct user flows and interactions with greater accuracy than screenshot-to-code tools.
• •Reduced Manual Effort: Eliminate the tedious task of manually recreating UI elements and interactions.
• •Enhanced Collaboration: Easily share video recordings with developers to communicate design and functionality requirements.
• •Rapid Prototyping: Quickly create prototypes of web applications by simply recording a video demonstration.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited usage, as well as paid plans for more advanced features and higher usage limits. Check the Replay pricing page for the latest details.

How is Replay different from v0.dev?#

While both Replay and v0.dev aim to generate code, they use fundamentally different approaches. v0.dev relies on text prompts, while Replay analyzes video recordings of user interactions. This allows Replay to understand user intent and generate more accurate and functional code. Replay excels at reconstructing existing UIs, while v0.dev is better for generating new UIs from scratch.

What types of applications can Replay generate?#

Replay can generate a wide range of web applications, from simple landing pages to complex dashboards. The key is to provide a clear and comprehensive video recording of the desired functionality.

What if the generated code isn't perfect?#

Replay's generated code is a great starting point, but it may require some manual adjustments. The Replay editor allows you to easily modify the code and fine-tune the application to your specific requirements. Think of it as a powerful code generation assistant, not a complete replacement for a developer.

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