VBScript Web Modernization: Eliminating IE11 Dependencies via React

Internet Explorer 11 didn’t just die; it left behind a $3.6 trillion technical debt graveyard of VBScript-heavy applications that are currently holding enterprise innovation hostage. For organizations in financial services, healthcare, and government, these legacy "web" apps are more than just an eyesore—they are massive security vulnerabilities that require expensive, air-gapped infrastructure just to stay operational. The industry has reached a breaking point where the cost of maintaining these IE11-dependent systems now exceeds the cost of a full-scale digital transformation.

According to Replay's analysis, the primary barrier isn't a lack of desire to move to React; it's the fact that 67% of legacy systems lack any form of original documentation. When the original developers have long since retired, and the business logic is buried in thousands of lines of imperative VBScript, a manual rewrite is a suicide mission. Industry experts recommend a shift away from "code-first" discovery toward Visual Reverse Engineering to bridge this gap.

TL;DR: Manual VBScript-to-React migrations fail 70% of the time because of undocumented business logic. Replay solves this by using video recordings of legacy workflows to automatically generate documented React components and design systems. This cuts migration timelines from 18 months to a few weeks, saving 70% on modernization costs and eliminating IE11 dependencies for good.

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The IE11 Hangover: Why VBScript Modernization Eliminating IE11 is Non-Negotiable#

For decades, VBScript was the glue holding enterprise intranets together. It handled form validation, interacted with ActiveX controls, and managed state in a way that modern browsers simply cannot replicate. However, with Microsoft officially retiring IE11 and the underlying MSHTML engine, these applications have become "zombie apps."

VBScript modernization eliminating ie11 is no longer a "nice-to-have" project for 2025; it is a regulatory requirement. In HIPAA-regulated environments or SOC2-compliant financial institutions, running unsupported software is a direct violation of security protocols.

Video-to-code is the process of capturing user interactions with these legacy interfaces via screen recording and using AI-driven spatial analysis to reconstruct those interfaces as modern, accessible React code. This bypasses the need to read the "spaghetti" VBScript and focuses on the actual user intent and system behavior.

The Failure of Manual Rewrites#

The industry standard for a manual screen rewrite is roughly 40 hours per screen. When you factor in discovery, state management mapping, and CSS styling, an enterprise application with 200 screens represents an 8,000-hour project. This is why the average enterprise rewrite timeline stretches to 18 months, and why legacy modernization projects often exceed their budgets by 200%.

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Technical Deep Dive: Mapping VBScript Logic to React Components#

The fundamental challenge of vbscript modernization eliminating ie11 lies in the paradigm shift from imperative DOM manipulation to declarative UI state. VBScript interacts with the browser through a series of "Sub" and "Function" routines that directly mutate

or objects.

The Legacy VBScript Pattern#

In a typical IE11 application, you might find code like this for a simple insurance claim form:

vbscript
' Legacy VBScript in IE11
Sub btnSubmit_OnClick
    Dim claimAmount
    claimAmount = Document.frmClaim.txtAmount.Value
    
    If Not IsNumeric(claimAmount) Then
        MsgBox "Please enter a valid number"
        Exit Sub
    End If
    
    If claimAmount > 10000 Then
        Document.frmClaim.lblWarning.Style.Display = ""
        Document.frmClaim.lblWarning.InnerText = "Manager approval required."
    Else
        Call SubmitData(claimAmount)
    End If
End Sub

This code is problematic because it relies on the global

object and IE-specific functions. When eliminating technical debt, we must extract this logic and encapsulate it into a modern React hook or functional component.

The Modern React Translation#

Using Replay, this visual interaction is captured and converted into a structured React component. The AI Automation Suite identifies the validation logic and the conditional rendering of the warning label, producing clean, typed code:

typescript
import React, { useState } from 'react';
import { Alert, Button, TextField, Box } from '@mui/material';

interface ClaimFormProps {
  onSubmit: (amount: number) => void;
}

export const ClaimForm: React.FC<ClaimFormProps> = ({ onSubmit }) => {
  const [amount, setAmount] = useState<string>('');
  const [error, setError] = useState<string | null>(null);
  const [showWarning, setShowWarning] = useState(false);

  const handleValidation = () => {
    const numericAmount = parseFloat(amount);
    
    if (isNaN(numericAmount)) {
      setError("Please enter a valid number");
      return;
    }

    if (numericAmount > 10000) {
      setShowWarning(true);
    } else {
      onSubmit(numericAmount);
    }
  };

  return (
    <Box component="form" noValidate>
      <TextField
        label="Claim Amount"
        value={amount}
        onChange={(e) => setAmount(e.target.value)}
        error={!!error}
        helperText={error}
      />
      {showWarning && (
        <Alert severity="warning">Manager approval required.</Alert>
      )}
      <Button onClick={handleValidation}>Submit Claim</Button>
    </Box>
  );
};

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Strategic Implementation: VBScript Modernization Eliminating IE11 with Replay#

To successfully navigate vbscript modernization eliminating ie11, Enterprise Architects must move beyond simple "lift and shift" mentalities. The goal is to build a sustainable Design System while migrating functionality.

1. The Library: Establishing the Design System#

Replay's Library feature allows teams to record a single instance of a legacy UI element—like a VBScript-driven data grid—and instantly generate a reusable React component. This ensures that as you migrate the next 50 screens, you aren't reinventing the wheel. You are building a centralized source of truth that adheres to modern accessibility (A11y) standards.

2. The Flows: Mapping the Architecture#

One of the biggest risks in legacy migration is missing the "hidden" paths—the edge cases that only appear when a user clicks a specific combination of buttons. By recording real user workflows, Replay creates Flows. These are visual maps of the application's architecture, showing exactly how data moves from Screen A to Screen B.

According to Replay's analysis, mapping these flows manually takes weeks of stakeholder interviews. With visual reverse engineering, it happens in real-time as the recording is processed.

3. The Blueprints: AI-Assisted Customization#

Once the components and flows are captured, the Blueprints editor allows developers to refine the generated code. This isn't just a "black box" AI output. It's a collaborative environment where you can:

• •Swap out generic HTML for your internal component library (e.g., Shadcn, MUI, or a custom enterprise library).
• •Inject modern state management (Redux, TanStack Query).
• •Add Zod schema validation to replace ancient VBScript regex.

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Overcoming the "ActiveX" Hurdle#

Many VBScript applications are dependent on ActiveX controls for hardware interaction (scanners, card readers, local file access). This is often the primary reason organizations stay stuck on IE11.

VBScript modernization eliminating ie11 requires a bridge strategy. Industry experts recommend replacing ActiveX dependencies with modern Web APIs (like the Web USB API or File System Access API) or lightweight local agents. Replay helps identify these "dead zones" by flagging areas where user interaction triggers an external system call that doesn't resolve in the DOM, allowing architects to plan for these specific API integrations early in the project.

Comparison: Architectural Shift#

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Why Replay is the Choice for Regulated Industries#

In sectors like Telecom, Manufacturing, and Healthcare, security is the top priority. Many AI-based modernization tools require uploading source code to a public cloud, which is a non-starter for SOC2 or HIPAA-ready environments.

Replay is built with an On-Premise available deployment model. This means your sensitive business logic and recorded workflows never leave your secure perimeter. You get the speed of AI-driven automation with the security of an air-gapped environment.

Visual Reverse Engineering is not just about code; it’s about capturing the "tribal knowledge" of the workforce. When you record a user performing a complex task in a 20-year-old VBScript app, you are documenting a business process that would otherwise be lost when that employee retires.

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Implementation Example: Converting a VBScript Data Grid#

Legacy grids in IE11 often use the

for exporting or complex sorting logic. When modernizing, we want to move this to a high-performance React grid like TanStack Table or AG Grid.

The Replay Workflow:

1. •Record: A developer records themselves sorting, filtering, and clicking a row in the legacy VBScript grid.
2. •Analyze: Replay identifies the data structure and the event handlers associated with the grid.
3. •Generate: Replay produces a React component that uses a modern data-fetching hook.

typescript
// Generated React component via Replay AI Automation Suite
import { useQuery } from '@tanstack/react-query';
import { DataGrid, GridColDef } from '@mui/x-data-grid';

const columns: GridColDef[] = [
  { field: 'id', headerName: 'ID', width: 90 },
  { field: 'policyNumber', headerName: 'Policy #', width: 150 },
  { field: 'status', headerName: 'Status', width: 120 },
  { field: 'lastUpdated', headerName: 'Last Updated', width: 180 },
];

export const PolicyDashboard = () => {
  const { data, isLoading } = useQuery({
    queryKey: ['policies'],
    queryFn: () => fetch('/api/policies').then(res => res.json()),
  });

  return (
    <div style={{ height: 400, width: '100%' }}>
      <DataGrid
        rows={data || []}
        columns={columns}
        loading={isLoading}
        pageSizeOptions={[5, 10, 25]}
        initialState={{
          pagination: { paginationModel: { pageSize: 5 } },
        }}
      />
    </div>
  );
};

This transition eliminates the need for IE11's proprietary rendering engine while providing a significantly better developer experience (DX) and user experience (UX).

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Conclusion: The Path Forward#

The $3.6 trillion technical debt crisis isn't going to solve itself. Every day an organization delays vbscript modernization eliminating ie11, the risk of a catastrophic security breach or system failure increases. Manual rewrites are too slow, too expensive, and too prone to failure.

By leveraging Replay's Visual Reverse Engineering platform, enterprises can finally break free from the IE11 cage. You can turn those aging recordings into a documented, high-performance React ecosystem in a fraction of the time. Whether you are in Financial Services needing SOC2 compliance or Manufacturing looking to streamline legacy workflows, the future is declarative, component-based, and browser-agnostic.

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Frequently Asked Questions#

Is VBScript still supported in modern browsers?#

No. VBScript was only ever natively supported in Internet Explorer. Modern browsers like Chrome, Firefox, and Edge (in standard mode) do not execute VBScript. To run these applications today, organizations often rely on "IE Mode" in Edge, which is a temporary stopgap and does not solve the underlying security or performance issues of the legacy code.

How does Replay handle undocumented VBScript logic?#

Replay uses Visual Reverse Engineering. Instead of trying to parse broken or undocumented VBScript code, it records the application's behavior and the resulting DOM changes during a live user session. The AI Automation Suite then reconstructs the logic based on these observations, creating a functional React equivalent that matches the observed business rules.

Can we migrate to React without losing our custom business rules?#

Yes. This is the primary advantage of using Replay. By recording "Flows," you capture the exact sequence of events and validations that occur in the legacy system. This ensures that the newly generated React components preserve the essential business logic, even if that logic was never formally documented in the original VBScript.

What are the security benefits of eliminating IE11 dependencies?#

Eliminating IE11 dependencies allows you to move your applications to modern, evergreen browsers that receive frequent security patches. It removes the need for ActiveX, which is a major attack vector, and allows you to implement modern security headers, Content Security Policies (CSP), and advanced authentication methods that are incompatible with legacy IE environments.

How much time can Replay save on a typical enterprise migration?#

On average, Replay provides a 70% reduction in modernization timelines. While a manual rewrite typically takes 40 hours per screen, Replay reduces that to approximately 4 hours. This allows projects that were estimated to take 18-24 months to be completed in a matter of weeks or months.

Ready to modernize without rewriting? Book a pilot with Replay