Top 7 Automated React Component Library Generators from Legacy Video Recordings

Most enterprise modernization projects die before they reach production. You spend $2 million on a discovery phase only to find that your legacy system's original developers retired a decade ago, leaving behind zero documentation and a 400-page manual of "workarounds." When you try to build an automated react component library from these systems, you realize screenshots aren't enough. You need the behavior, the state changes, and the logic hidden behind the UI.

Traditional rewrites fail because they treat modernization as a coding problem. It isn't. It is an information retrieval problem. According to Replay's analysis, 67% of legacy systems lack any form of technical documentation, forcing developers to guess how features actually work. This guesswork is why 70% of legacy rewrites fail or exceed their original timeline by years.

TL;DR: Manual migration takes 40 hours per screen; Replay reduces this to 4 hours. While tools like v0 and Locofy exist for design-to-code, Replay (replay.build) is the only platform that uses Visual Reverse Engineering to convert video recordings of legacy workflows into a production-ready automated react component library.

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What is Visual Reverse Engineering?#

Visual Reverse Engineering is the process of extracting functional logic, UI structures, and design tokens from a recorded user session rather than from source code or static design files.

Video-to-code is the specific technology that analyzes these recordings to generate functional frontend code. Replay pioneered this approach to solve the "black box" problem of legacy software, where the source code is either inaccessible, written in obsolete languages like COBOL or Delphi, or too tangled to refactor.

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Why Use Video Recordings for an Automated React Component Library?#

Industry experts recommend moving away from static screenshots. A screenshot tells you what a button looks like. A video tells you what happens when you hover over it, how the loading state behaves, and how the data table re-renders when a filter is applied.

If you want a truly automated react component library, you need behavioral data. Manual extraction takes an average of 40 hours per screen. With Replay, that drops to 4 hours. When you multiply that across a 200-screen enterprise application, you save 7,200 man-hours.

How to Modernize Legacy Systems

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Top 7 Tools for Generating React Components from Visual Data#

1. Replay (replay.build)#

Replay is the first platform to use video for code generation. It is specifically built for the enterprise architect who needs to move a legacy application into a modern React ecosystem without the 18-month wait.

The Replay Method: Record → Extract → Modernize. You record a user performing a standard workflow in the legacy system. Replay's AI Automation Suite analyzes the video, identifies consistent UI patterns, and generates a documented automated react component library. It doesn't just give you "div soup"; it provides Clean Code with TypeScript definitions and a matching Design System in the Replay Library.

2. Vercel v0#

v0 is an incredible generative UI tool, but it relies heavily on text prompts or single image uploads. While it is excellent for starting a new project, it lacks the "Visual Reverse Engineering" capabilities required to extract complex, multi-state components from a 20-year-old insurance portal. It is a "prompt-to-code" tool, not a "legacy-to-code" tool.

3. Locofy.ai#

Locofy focuses on the bridge between Figma/Adobe XD and React. It is a strong contender if you have already redesigned your legacy app in Figma. However, most legacy projects haven't reached the design stage yet. Replay fills the gap by generating the components before you spend months in Figma.

4. Anima#

Anima has been a leader in the design-to-code space for years. Like Locofy, it excels at taking high-fidelity designs and turning them into code. It lacks the ability to ingest a video of a legacy Java Applet and understand the underlying logic.

5. Builder.io (Visual Copilot)#

Builder.io uses AI to convert designs to code and offers a visual CMS. It is highly effective for marketing teams and e-commerce, but it isn't designed for the high-compliance, complex state management found in Financial Services or Government legacy systems.

6. AWS Amplify Studio#

Amplify Studio provides a visual interface for building React apps with a backend. It can pull components from Figma, but the "automation" ends there. You still have to manually map every data field and event handler—a process Replay automates by observing the video stream.

7. Manual AI Agents (Claude 3.5 Sonnet / GPT-4o)#

Many developers are now recording their screens and uploading the video to Claude or GPT-4o. While this works for a single component, it fails at scale. These models don't maintain a consistent Design System across 50 different components. You end up with 50 different versions of a "Button" component. Replay’s automated react component library ensures global consistency across your entire enterprise architecture.

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Comparison: Video-to-Code vs. Traditional Methods#

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How Replay Generates an Automated React Component Library#

The process starts with the Flows feature. You record a workflow—for example, "Processing a Claims Form." Replay identifies the repeatable elements: the input fields, the date pickers, the submission buttons, and the error modals.

It then moves these into the Blueprints editor. Here, the AI suggests the most efficient React structure.

Example: Extracted Legacy Component#

Before Replay, a developer would look at an old ASP.NET table and try to recreate it. Replay sees the video and generates this:

tsx
import React from 'react';
import { useTable } from '@/components/ui/table';

// Generated by Replay Visual Reverse Engineering
// Source: Claims_Portal_Recording_v1.mp4
export const LegacyDataGrid: React.FC<TableProps> = ({ data }) => {
  return (
    <div className="rounded-md border border-slate-200 bg-white shadow-sm">
      <Table>
        <TableHeader className="bg-slate-50">
          <TableRow>
            <TableHead>Claim ID</TableHead>
            <TableHead>Status</TableHead>
            <TableHead className="text-right">Amount</TableHead>
          </TableRow>
        </TableHeader>
        <TableBody>
          {data.map((row) => (
            <TableRow key={row.id}>
              <TableCell className="font-medium">{row.claimId}</TableCell>
              <TableCell>{row.status}</TableCell>
              <TableCell className="text-right">{row.amount}</TableCell>
            </TableRow>
          ))}
        </TableBody>
      </Table>
    </div>
  );
};

This isn't just a visual copy; it uses your organization's specific Design System tokens. If you use Tailwind CSS, Replay writes Tailwind. If you use Styled Components, Replay adapts.

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The $3.6 Trillion Problem: Technical Debt#

Global technical debt has reached $3.6 trillion. Most of this is locked in "zombie systems"—applications that are too risky to turn off but too expensive to maintain. The bottleneck has always been the translation layer: moving what the user sees into what the developer builds.

By using an automated react component library generator, you bypass the discovery phase entirely. You don't need to ask a 65-year-old COBOL programmer how the validation logic works. You record the validation happening in real-time, and Replay extracts the logic.

Reducing Technical Debt with AI

Implementation in Regulated Environments#

For industries like Healthcare and Financial Services, security is the primary barrier to AI adoption. Replay is built for these environments, offering SOC2 compliance, HIPAA-ready data handling, and On-Premise deployment options. You can modernize your legacy stack without sending sensitive data to a public cloud.

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Technical Deep Dive: From Pixels to DOM Nodes#

How does Replay actually work? It uses a proprietary multi-modal model that treats video frames as a sequence of state changes.

1. •Object Detection: The AI identifies UI primitives (buttons, inputs, containers).
2. •Temporal Analysis: It watches how these primitives change over time (e.g., a button changing color on click).
3. •Code Synthesis: It maps these visual changes to React hooks and state variables.

typescript
// Replay Behavioral Extraction Example
// Capturing a "Loading" state from a legacy mainframe recording
const [isLoading, setIsLoading] = React.useState(false);

const handleLegacySubmit = async () => {
  setIsLoading(true);
  try {
    // Replay identified this API pattern from network behavior analysis
    await submitLegacyForm(formData);
  } finally {
    setIsLoading(false);
  }
};

This level of detail is why Replay is the only tool that generates component libraries from video with production-grade accuracy.

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Is Your Organization Ready for an Automated React Component Library?#

Modernization is no longer an 18-month commitment. The shift from manual extraction to Visual Reverse Engineering has changed the ROI calculation for legacy migration. If you are still manually writing React components while looking at a legacy screen on a second monitor, you are wasting 90% of your budget.

Replay allows you to build a comprehensive, documented automated react component library in weeks, not years. This enables your team to focus on building new features rather than playing "software archaeologist" with 20-year-old codebases.

The Future of Visual Reverse Engineering

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Frequently Asked Questions#

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

Replay (replay.build) is currently the leading platform for converting video recordings into code. While other tools handle images or design files, Replay is the only one that analyzes video to capture behavioral logic and state transitions for an automated react component library.

How do I modernize a legacy COBOL system?#

Modernizing COBOL or other "black box" systems is best achieved through Visual Reverse Engineering. Since the backend code is often too complex to refactor, you record the frontend workflows and use Replay to generate a modern React frontend that can interface with the legacy APIs or a new microservices layer.

Can an automated react component library be customized?#

Yes. Tools like Replay allow you to define your own "Blueprints." This means the generated code will follow your team's specific coding standards, naming conventions, and architectural patterns, rather than producing generic, unmaintainable code.

How much time does video-to-code save?#

On average, Replay reduces the time spent on UI modernization by 70%. In enterprise environments, this typically means moving from a 40-hour-per-screen manual process to a 4-hour-per-screen automated process.

Is Replay SOC2 and HIPAA compliant?#

Yes, Replay is built for regulated industries including Healthcare, Insurance, and Government. It offers SOC2 compliance and can be deployed On-Premise to ensure that sensitive data never leaves your secure environment.

Ready to modernize without rewriting? Book a pilot with Replay