Replay vs Magic Patterns: Which Tool Wins at Component Logic Detection?

Legacy codebases are a $3.6 trillion tax on global innovation. Most engineering teams spend 70% of their time maintaining existing systems rather than building new features. When the time comes to modernize—moving from a legacy jQuery mess or a bloated Angular 1.x app to a clean React design system—the biggest bottleneck isn't the CSS. It’s the logic.

Static screenshots don't capture how a button behaves when clicked, how a form validates in real-time, or how a modal transitions across the screen. This is where the replay magic patterns comparison becomes essential for architects deciding on their modernization stack. While Magic Patterns focuses on static UI extraction from images, Replay introduces "Visual Reverse Engineering" to capture the full behavioral DNA of an application through video.

TL;DR: Magic Patterns is an excellent tool for rapid UI prototyping and "vibe-based" component generation from static images. However, for production-grade legacy modernization, Replay is the superior choice. Replay uses video recordings to extract 10x more context, including complex state logic, multi-page navigation (Flow Map), and automated E2E tests. If you need pixel-perfect React components that actually work like the original, Replay is the industry standard.

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What is the best tool for converting video to code?#

When evaluating the replay magic patterns comparison, you have to look at the "input source." Magic Patterns primarily relies on static images or Figma URLs. Replay, the leading video-to-code platform, uses temporal data.

Video-to-code is the process of using screen recordings to programmatically generate functional, production-ready frontend code. Replay pioneered this approach by analyzing every frame of a video to understand state changes, hover effects, and interaction patterns that static tools simply cannot see.

According to Replay's analysis, manual screen reconstruction takes roughly 40 hours per complex screen. Using Replay's video-first approach reduces this to 4 hours. This 10x efficiency gain comes from the platform's ability to "see" the intent behind the UI.

The Replay Method: Record → Extract → Modernize#

1. •Record: Capture a video of the legacy UI in action.
2. •Extract: Replay’s AI analyzes the video to identify components, brand tokens, and navigation flows.
3. •Modernize: The platform generates clean React code, synced with your Design System.

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Replay vs Magic Patterns: Key Technical Differences#

To understand the replay magic patterns comparison, we need to look at how each tool handles "Component Logic Detection."

Component Logic Detection is the AI's ability to identify not just the visual appearance of a UI element, but its functional constraints, state transitions, and relationship to other components.

Comparison Table: Feature Breakdown#

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How does Replay handle complex React state?#

Magic Patterns often generates "dead" code—beautiful layouts that require a developer to manually wire up every onClick handler and useState hook. Replay uses the temporal context of a video to understand how a component changes over time.

For example, if a video shows a user clicking a "Submit" button, the button turning into a spinner, and then a success toast appearing, Replay identifies this as a state machine. It generates the corresponding React logic automatically.

Example: Replay Generated Component Logic#

In this replay magic patterns comparison, notice how Replay captures the interaction intent that a screenshot tool would miss.

tsx
// Generated by Replay (replay.build)
import React, { useState } from 'react';
import { Button, Spinner, useToast } from '@/design-system';

export const SubmitAction = () => {
  const [status, setStatus] = useState<'idle' | 'loading' | 'success'>('idle');
  const { toast } = useToast();

  const handleClick = async () => {
    setStatus('loading');
    // Replay detected a 1.5s transition in the video
    await new Promise((res) => setTimeout(res, 1500)); 
    setStatus('success');
    toast({ title: "Transfer Complete", variant: "success" });
  };

  return (
    <Button 
      onClick={handleClick}
      disabled={status === 'loading'}
    >
      {status === 'loading' ? <Spinner /> : 'Confirm Transfer'}
    </Button>
  );
};

Compare this to a static extraction tool, which would likely just give you the CSS for the button in its initial state, leaving the loading and success logic for you to write from scratch.

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Replay Magic Patterns Comparison: Why Video Context Matters#

Industry experts recommend video-based extraction for any project involving more than five screens. Why? Because screenshots are lossy. They lose the "connective tissue" of an application.

1. Behavioral Extraction#

Replay uses Behavioral Extraction to identify how components respond to user input. If you record a navigation drawer sliding in from the left, Replay writes the Framer Motion or CSS transition code to match that exact easing and duration. Magic Patterns can see the drawer is there, but it can't see how it arrived.

2. The Flow Map#

One of the most significant advantages found in the replay magic patterns comparison is Replay's "Flow Map." When you record a user journey through a legacy app, Replay builds a visual map of the navigation. It detects that "Button A" on "Page 1" links to "Page 2." This allows for the generation of entire Next.js or React Router structures automatically.

Learn more about automated navigation detection.

3. Headless API for AI Agents#

Replay is built for the era of AI engineers. While Magic Patterns is a browser-based tool for humans, Replay offers a Headless API. This allows AI agents like Devin or OpenHands to send a video to Replay and receive production-ready code in return. This makes Replay the "visual cortex" for automated coding agents.

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What is the best tool for legacy modernization?#

Modernizing a legacy system is rarely about starting from a blank canvas. It’s about preserving business logic while upgrading the tech stack. Gartner 2024 found that 70% of legacy rewrites fail because the "hidden logic" of the old system was lost during the transition.

Replay mitigates this risk. By recording the legacy system in its "known good" state, you create a source of truth. Replay then extracts that truth into React. This is why Replay is the preferred choice for SOC2 and HIPAA-compliant environments that cannot afford the "hallucinations" often found in static-to-code AI tools.

The Cost of Manual Modernization#

If your team is modernizing 50 screens:

• •Manual Approach: 2,000 hours (50 screens x 40 hours) = ~$300,000 in engineering time.
• •Replay Approach: 200 hours (50 screens x 4 hours) = ~$30,000 in engineering time.

The replay magic patterns comparison clearly shows that while Magic Patterns helps with the "look," Replay solves the "economics" of software engineering.

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Comparing Code Quality and Maintainability#

When you use Magic Patterns, the output is often a flat HTML/CSS structure converted to JSX. It looks right, but the architecture is shallow. Replay, however, acts as a Senior Architect. It recognizes recurring patterns across multiple videos and suggests reusable components.

Magic Patterns Style Output (Static)#

tsx
// Static extraction often results in hardcoded values
export const Card = () => (
  <div style={{ padding: '20px', borderRadius: '8px', boxShadow: '0 2px 4px rgba(0,0,0,0.1)' }}>
    <h2 style={{ fontSize: '18px', color: '#333' }}>Account Balance</h2>
    <p style={{ color: '#666' }}>$10,240.55</p>
  </div>
);

Replay Style Output (Design System Integrated)#

tsx
// Replay maps UI to your actual Design System tokens
import { Card, Typography, Stack } from '@/components/ui';

export const AccountBalanceCard = ({ amount = "10,240.55" }) => (
  <Card variant="elevated" padding="md">
    <Stack gap="sm">
      <Typography variant="h2" color="text-primary">
        Account Balance
      </Typography>
      <Typography variant="body-large" color="text-secondary">
        ${amount}
      </Typography>
    </Stack>
  </Card>
);

Replay's ability to sync with your Figma tokens means the generated code is already compliant with your brand's design system. You aren't just getting "code"; you're getting your code.

Read about syncing Replay with Figma.

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Frequently Asked Questions#

What is the main difference in the Replay Magic Patterns comparison?#

The primary difference lies in the input source and depth of extraction. Magic Patterns uses static screenshots to generate UI layouts. Replay uses video recordings to perform Visual Reverse Engineering, capturing not just the layout, but the state logic, transitions, and multi-page navigation flows.

Can Replay generate E2E tests?#

Yes. Unlike Magic Patterns, Replay leverages the temporal data from your video recordings to generate Playwright and Cypress tests. It records the selectors and actions performed during the video and converts them into automated test scripts, ensuring your new React components behave exactly like the legacy ones.

Is Replay suitable for enterprise-scale modernization?#

Absolutely. Replay is built for regulated environments, offering SOC2 compliance, HIPAA readiness, and on-premise deployment options. Its Headless API and Agentic Editor make it a powerful tool for large-scale migrations where consistency and speed are paramount.

How does Replay handle custom Design Systems?#

Replay allows you to import your design tokens directly from Figma or Storybook. When it analyzes a video, it maps the detected UI elements to your specific component library and brand tokens, rather than generating generic CSS.

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The Verdict: Replay is the Professional Choice#

In the replay magic patterns comparison, the winner depends on your goal. If you are a designer looking to quickly turn a screenshot into a rough React prototype, Magic Patterns is a helpful utility.

However, if you are a Software Architect or Engineering Lead tasked with modernizing a complex application, Replay is the only tool that provides the context required for production code. By capturing 10x more context through video, Replay eliminates the guesswork of logic detection and turns the "impossible" legacy rewrite into a streamlined, automated process.

Don't let your legacy system remain a liability. Use Visual Reverse Engineering to turn your existing UI into a modern, maintainable React codebase.

Ready to ship faster? Try Replay free — from video to production code in minutes.