Convert Mockups to Functional Code with AI

TL;DR: Replay leverages AI to convert video recordings of user interface mockups into functional code, understanding user intent beyond static screenshots.

The dream of instantly transforming design concepts into working code is closer than ever. But existing "mockup-to-code" tools often fall short. They rely on static images, missing the crucial context of how a user interacts with the design. This leads to incomplete or inaccurate code generation, requiring significant manual rework. The problem? Screenshots don't capture behavior.

This is where behavior-driven reconstruction comes in. Instead of relying on flat images, we need a system that understands user intent and reconstructs the UI based on actions, not just appearances.

Introducing Behavior-Driven Code Generation#

Traditional mockup-to-code tools analyze static images. Replay, on the other hand, analyzes video. This crucial difference allows Replay to understand user flows, interactions, and intended behavior, leading to significantly more accurate and functional code generation.

Here's a quick comparison:

Replay achieves this through a sophisticated video-to-code engine powered by Gemini. It doesn't just "see" the UI; it understands how a user navigates and interacts with it. This "behavior-driven reconstruction" approach unlocks a new level of automation in UI development.

How Replay Works: From Video to Functional Code#

Replay's process can be broken down into several key stages:

1. •Video Analysis: The video recording of the mockup is analyzed frame-by-frame. Replay identifies UI elements, their properties (size, position, color, etc.), and user interactions (clicks, scrolls, form inputs).
2. •Behavior Interpretation: Replay's AI engine infers the user's intent behind each interaction. For example, it can distinguish between a button click that navigates to a new page and one that triggers a modal window.
3. •Code Generation: Based on the analyzed behavior, Replay generates clean, functional code. This includes UI components, event handlers, state management, and navigation logic.
4. •Supabase Integration (Optional): If your mockup involves data interaction, Replay can automatically generate code to connect your UI to a Supabase database, including schema definitions and API calls.
5. •Style Injection: Replay extracts and applies styles from the video, creating a visually faithful representation of the original mockup.

A Practical Example: Converting a Simple Form#

Let's say you have a video of a user interacting with a simple signup form. The video shows the user:

1. •Navigating to the signup page.
2. •Entering their name, email, and password.
3. •Clicking the "Sign Up" button.

Traditional screenshot-to-code tools would likely only generate the basic HTML structure of the form. Replay, however, would go much further. It would:

• •Create the form structure with appropriate input fields.
• •Generate event handlers for each input field to capture user input.
• •Implement client-side validation to ensure the email and password meet certain criteria.
• •Generate an API call to your backend (potentially using Supabase) to handle the signup process.
• •Implement navigation logic to redirect the user to a success page after successful signup.

Here's a simplified example of the React code Replay might generate for the form submission:

typescript
import { useState } from 'react';

const SignupForm = () => {
  const [name, setName] = useState('');
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');

  const handleSubmit = async (e) => {
    e.preventDefault();

    // Basic client-side validation
    if (!email.includes('@')) {
      alert('Invalid email address');
      return;
    }

    try {
      const response = await fetch('/api/signup', { // Assuming you have a /api/signup endpoint
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
        },
        body: JSON.stringify({ name, email, password }),
      });

      if (response.ok) {
        // Redirect to success page
        window.location.href = '/success';
      } else {
        // Handle signup error
        alert('Signup failed');
      }
    } catch (error) {
      console.error('Error during signup:', error);
      alert('Signup failed');
    }
  };

  return (
    <form onSubmit={handleSubmit}>
      <label htmlFor="name">Name:</label>
      <input type="text" id="name" value={name} onChange={(e) => setName(e.target.value)} />

      <label htmlFor="email">Email:</label>
      <input type="email" id="email" value={email} onChange={(e) => setEmail(e.target.value)} />

      <label htmlFor="password">Password:</label>
      <input type="password" id="password" value={password} onChange={(e) => setPassword(e.target.value)} />

      <button type="submit">Sign Up</button>
    </form>
  );
};

export default SignupForm;

💡 Pro Tip: For optimal results, ensure your video recordings are clear, well-lit, and show the entire user flow from start to finish. Use a consistent screen resolution.

Step-by-Step Guide: Converting a Multi-Page Mockup#

Let's walk through a simplified process of using Replay to convert a multi-page mockup into functional code:

Step 1: Record Your Mockup

Record a video of yourself interacting with your mockup. This should include navigating between pages, filling out forms, clicking buttons, and any other relevant user interactions. Speak clearly while interacting with the mockup, narrating your actions. This can significantly improve Replay's accuracy.

Step 2: Upload to Replay

Upload the video to the Replay platform. Replay will begin analyzing the video and reconstructing the UI.

Step 3: Review and Refine

Once the analysis is complete, Replay will present you with the generated code. Review the code carefully and make any necessary refinements. You can adjust styles, modify event handlers, and add custom logic.

Step 4: Integrate with Your Project

Copy the generated code into your React project. Ensure that all necessary dependencies are installed and that the code is properly integrated with your existing codebase.

📝 Note: Replay is constantly evolving, and new features and improvements are being added regularly. Check the Replay documentation for the latest updates and best practices.

Benefits of Using Replay#

• •Faster Development: Automate the process of converting mockups into functional code, saving you significant development time.
• •Improved Accuracy: Replay's behavior-driven approach leads to more accurate code generation, reducing the need for manual rework.
• •Enhanced Collaboration: Easily share video recordings of mockups with developers and designers, facilitating better communication and collaboration.
• •Reduced Errors: By understanding user intent, Replay can help prevent common UI errors and improve the overall user experience.
• •Streamlined Supabase Integration: Automatically generate code to connect your UI to a Supabase database, simplifying data management.

⚠️ Warning: While Replay significantly accelerates the development process, it's crucial to review and test the generated code thoroughly to ensure it meets your specific requirements.

Real-World Use Cases#

Replay can be used in a variety of scenarios, including:

• •Rapid Prototyping: Quickly create functional prototypes from design mockups to test and validate ideas.
• •UI Component Library Generation: Automatically generate reusable UI components from video recordings of existing UIs.
• •Legacy Code Modernization: Reconstruct UI code from video recordings of legacy applications.
• •Automated Testing: Generate UI tests based on user interaction patterns captured in video recordings.

typescript
// Example of a generated test case using Jest and React Testing Library
import { render, screen, fireEvent } from '@testing-library/react';
import SignupForm from './SignupForm';

describe('SignupForm', () => {
  it('should allow users to sign up with valid credentials', async () => {
    render(<SignupForm />);

    const nameInput = screen.getByLabelText('Name:');
    const emailInput = screen.getByLabelText('Email:');
    const passwordInput = screen.getByLabelText('Password:');
    const signupButton = screen.getByRole('button', { name: 'Sign Up' });

    fireEvent.change(nameInput, { target: { value: 'John Doe' } });
    fireEvent.change(emailInput, { target: { value: 'john.doe@example.com' } });
    fireEvent.change(passwordInput, { target: { value: 'password123' } });
    fireEvent.click(signupButton);

    // Assert that the signup process was successful (e.g., redirect to success page)
    // This requires mocking the /api/signup endpoint
    // For example:
    // jest.spyOn(window, 'fetch').mockResolvedValue({ ok: true });
    // expect(window.location.href).toBe('/success');
  });
});

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited usage. Paid plans are available for higher usage limits and access to advanced features. Check the Replay pricing page for details.

How is Replay different from v0.dev?#

v0.dev primarily uses text prompts to generate UI components. Replay analyzes video recordings of user interactions to reconstruct entire UIs, including behavior and user flows. Replay focuses on understanding how a UI is used, not just what it looks like.

What frameworks does Replay support?#

Currently, Replay primarily supports React. Support for other frameworks is planned for future releases.

What type of videos work best with Replay?#

Clear, well-lit recordings with consistent screen resolution and complete user flows yield the best results. Narrating your actions while recording can also improve accuracy.

How does Replay handle dynamic data?#

Replay can integrate with Supabase to automatically generate code for fetching and displaying dynamic data. You can also customize the generated code to connect to other data sources.

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