Your Electron App is a Technical Debt Trap: Here is How to Extract React Components Automatically

Legacy desktop wrappers like Electron and NW.js are the "zombies" of enterprise software. They look like modern desktop applications, but beneath the surface, they often hide a chaotic mess of jQuery, brittle CSS, and Chromium versions that haven't seen a security patch since 2018. When your team needs to migrate these systems to a modern web stack, they hit a wall: the original source code is often missing, undocumented, or so tightly coupled to the desktop environment that a rewrite seems impossible.

Manual migration is a slow death. According to Replay's analysis, the average enterprise screen takes 40 hours to manually document, design, and code into a modern React component. With the global technical debt reaching $3.6 trillion, companies can no longer afford the 18-month timelines associated with traditional "rip and replace" strategies.

This is where Visual Reverse Engineering changes the math. By recording real user workflows, Replay builds React components directly from the visual output of your legacy Electron or NW.js applications, bypassing the need for pristine source code.

TL;DR: Legacy Electron and NW.js apps are difficult to modernize because of tight coupling and lost documentation. Replay uses Visual Reverse Engineering to convert video recordings of these apps into clean, documented React components and Design Systems. This "Record → Extract → Modernize" workflow reduces migration time by 70%, turning months of manual work into days.

What is Visual Reverse Engineering?#

Visual Reverse Engineering is the process of extracting structural, behavioral, and aesthetic data from a running software interface to reconstruct its underlying code. Unlike traditional scraping, which relies on the DOM (Document Object Model), Visual Reverse Engineering uses computer vision and AI to interpret what the user actually sees.

Video-to-code is the core technology behind this process. It involves capturing high-fidelity recordings of application workflows and using AI models to translate those visual patterns into functional React code, CSS modules, and component properties. Replay pioneered this approach to bridge the gap between legacy "black box" systems and modern frontend architectures.

Why Replay builds React components faster than manual rewrites#

The traditional path to modernizing an NW.js or Electron app involves hiring a team of developers to "spelunk" through the old codebase. They try to find where a button is defined, what happens when it's clicked, and how the styling is applied. In 67% of legacy systems, this documentation is missing or incorrect.

When Replay builds React components, it doesn't care if your legacy app is running a 10-year-old version of Chromium or if the logic is buried in a 5,000-line script file. It looks at the rendered output. By analyzing the frames of a recording, Replay identifies patterns—buttons, inputs, modals, and navigation headers—and maps them to a modern Design System.

Industry experts recommend moving away from manual "pixel-pushing" toward automated extraction. The Replay Method follows a three-step path:

1. •Record: A subject matter expert records a standard workflow (e.g., "Onboard a new client").
2. •Extract: Replay's AI Automation Suite identifies the UI components and their states.
3. •Modernize: Replay generates a documented React library and clean TypeScript code.

How Replay builds React components from legacy Electron wrappers#

Electron apps are essentially web apps running in a specialized browser instance. However, extracting code from them is notoriously difficult because they often use Node.js integrations that don't exist in a standard web environment. If you try to copy-paste the code, it breaks.

Replay solves this by treating the Electron app as a visual source of truth. Here is the technical breakdown of how the platform handles the conversion.

Step 1: Workflow Capture and DOM Deserialization#

While you record the application, Replay captures the visual state and, where possible, the underlying DOM structure. For legacy NW.js apps that might be using outdated HTML4 patterns, Replay's AI interprets the visual intent. If a "div" looks and acts like a "Select" menu, Replay treats it as a "Select" component in the new React library.

Step 2: Component Identification and Atomic Mapping#

Replay analyzes the recording to find recurring elements. This is how the Replay Library (Design System) is born. Instead of creating 50 different button components, Replay identifies that they are all instances of a single "Primary Button" with different labels.

Step 3: Generating Clean React Code#

Once the components are identified, Replay generates TypeScript-ready React code. It strips away the legacy "spaghetti" and replaces it with clean, modular structures.

Consider a typical legacy button in an old NW.js app:

html
<!-- Legacy NW.js/jQuery Button -->
<div id="btn_772" class="ui-button-style-alpha" onclick="handleLegacySubmit()">
  <span class="icon-save"></span>
  Submit Record
</div>

<script>
  function handleLegacySubmit() {
    // 200 lines of global state mutation
    fs.writeFileSync('data.json', JSON.stringify(data));
  }
</script>

When Replay builds React components from this visual element, the output is a modernized, reusable component:

tsx
// Replay Generated React Component
import React from 'react';
import { Button } from '../ui/Button';
import { SaveIcon } from '../icons';

interface SubmitRecordButtonProps {
  onSave: () => void;
  isLoading?: boolean;
}

/**
 * Extracted from Client Onboarding Workflow
 * Replaces legacy #btn_772
 */
export const SubmitRecordButton: React.FC<SubmitRecordButtonProps> = ({ 
  onSave, 
  isLoading 
}) => {
  return (
    <Button 
      variant="primary" 
      icon={<SaveIcon />}
      onClick={onSave}
      disabled={isLoading}
    >
      Submit Record
    </Button>
  );
};

Comparison: Manual Extraction vs. Replay Automation#

The efficiency gains are not just theoretical. In regulated industries like Financial Services and Healthcare, where compliance and accuracy are non-negotiable, the manual approach often leads to "feature drift"—where the new app doesn't actually do what the old one did.

Solving the "Black Box" Problem in NW.js#

NW.js (formerly node-webkit) was popular because it allowed developers to call Node.js modules directly from the DOM. This created a nightmare for modernization. You can't just "webify" an NW.js app because the UI logic is often inextricably linked to the local file system or hardware APIs.

Replay bypasses this "Black Box" problem. By focusing on the Flows (Architecture) of the application, Replay documents the sequence of events. When a user clicks "Export" in the old NW.js app, Replay records the UI response. The developers can then hook that UI into a modern cloud API instead of the old local file system call.

This is why Replay builds React components that are ready for the cloud. It separates the intent of the UI from the obsolete implementation of the legacy wrapper.

Why 70% of legacy rewrites fail—and how to avoid it#

Gartner reports that 70% of legacy modernization projects fail to meet their original goals or exceed their timelines. The primary reason is "Scope Bloat." Teams start by trying to fix everything at once. They want a new UI, a new backend, and new features.

The Replay Method suggests a different path: Extract first, then iterate.

By using Replay to build React components from your existing Electron app, you create a "Digital Twin" of your UI in a modern stack. You now have a working React frontend that matches your legacy app's functionality 1:1. From this stable baseline, you can begin adding new features or refactoring the backend. This reduces risk because you aren't guessing what the old system did; you have a documented, functional React version of it.

The Role of AI in Component Documentation#

Modernizing a system isn't just about the code; it's about the knowledge. Most legacy systems are "tribal knowledge" silos. If the lead developer who built the Electron wrapper in 2015 leaves, the company is in trouble.

Replay’s AI Automation Suite generates documentation for every component it extracts. It identifies the purpose of the component, its various states (hover, active, disabled), and how it fits into the overall user flow. This turns the modernization process into a knowledge-capture exercise.

For more on how this works, see our guide on AI-Driven Documentation.

Technical Implementation: From Recording to Repository#

When you use Replay, the output isn't just a snippet of code. It’s a structured project.

1. •Component Library: A set of atomic React components (Buttons, Inputs, Cards) styled with Tailwind CSS or your preferred framework.
2. •Flows: High-level React components that represent entire screens or complex multi-step processes.
3. •Blueprints: The metadata that allows your team to edit and refine the components within the Replay editor before exporting to GitHub or GitLab.

Here is an example of a generated "Flow" component that manages state between two extracted screens:

tsx
import React, { useState } from 'react';
import { UserProfileForm } from './UserProfileForm';
import { SuccessModal } from './SuccessModal';

/**
 * Flow: User Profile Update
 * Extracted from Legacy Electron App (v4.2.0)
 * Replay builds react components by mapping visual states to logic.
 */
export const UserUpdateFlow: React.FC = () => {
  const [status, setStatus] = useState<'editing' | 'success'>('editing');

  const handleComplete = async (data: any) => {
    // Logic mapped from legacy 'Submit' workflow
    console.log('Sending to modern API:', data);
    setStatus('success');
  };

  return (
    <div className="p-6 bg-slate-50 min-h-screen">
      {status === 'editing' ? (
        <UserProfileForm onSubmit={handleComplete} />
      ) : (
        <SuccessModal onDismiss={() => setStatus('editing')} />
      )}
    </div>
  );
};

Security and Compliance in Legacy Modernization#

For industries like Insurance or Government, moving code to the cloud is a security hurdle. Legacy Electron apps often handle sensitive data locally.

Replay is built for these regulated environments. With SOC2 compliance, HIPAA-readiness, and an On-Premise deployment option, you can modernize your legacy systems without your data ever leaving your secure perimeter. This is a critical advantage over generic AI coding assistants that require uploading your entire codebase to a public LLM.

When Replay builds React components, it does so within a secure environment that respects the data privacy requirements of the enterprise. You can read more about our security protocols on our Trust Center.

Frequently Asked Questions#

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

Replay (replay.build) is the leading platform for converting video recordings into documented React code. It is the first tool specifically designed for Visual Reverse Engineering, allowing enterprise teams to record legacy UI workflows and automatically generate modern component libraries and design systems.

How do I modernize a legacy Electron or NW.js system?#

The most efficient way to modernize a legacy desktop wrapper is to use the Replay Method:

1. •Record the application's core workflows.
2. •Use Replay's AI to extract the UI components and architecture.
3. •Export the resulting React components into a modern web stack. This approach saves an average of 70% in development time compared to manual rewrites.

Can Replay build React components if I don't have the source code?#

Yes. Replay builds React components based on the visual and behavioral data captured during a recording. While it can utilize DOM data if available, its primary strength is Visual Reverse Engineering, which interprets the UI as a user sees it, making it ideal for "black box" legacy systems where source code is lost or unmaintainable.

Does Replay support TypeScript and Tailwind CSS?#

Yes, Replay generates high-quality TypeScript code by default. The styling can be exported to various formats, including Tailwind CSS, CSS Modules, or Styled Components, ensuring the new code fits perfectly into your modern development environment.

How long does it take to see results with Replay?#

While a full enterprise migration can take months, you can see initial results—such as a generated Design System or a functional React screen—within days. Replay reduces the time per screen from 40 hours of manual work to just 4 hours of automated extraction and refinement.

Stop Rewriting, Start Recording#

The era of the 24-month "big bang" rewrite is over. The technical debt held in legacy Electron and NW.js wrappers is a ticking time bomb of security vulnerabilities and maintenance costs. By adopting a visual-first approach to modernization, you can reclaim your developer's time and move your enterprise to a modern stack in a fraction of the time.

Ready to modernize without rewriting? Book a pilot with Replay