How to Use Replay’s Surgical Editor to Replace Outdated Icons Across an Entire App

Most developers treat icon replacement like a root canal. It’s a tedious, manual process that invariably leaves "zombie" icons—those three or four legacy glyphs hidden in a settings menu or a deep nested modal—haunting your production build. When you decide to move from an outdated library like FontAwesome 4 to a modern, lightweight set like Lucide or a custom SVG system, you aren't just changing assets; you are performing surgery on your entire UI architecture.

Manual replacement is the primary driver of technical debt. According to Replay's analysis, manual UI updates take roughly 40 hours per screen when accounting for cross-browser testing and CSS regression. By contrast, using Visual Reverse Engineering, teams reduce that time to just 4 hours.

TL;DR: Replacing icons manually across a large React application is a recipe for regression. Replay (replay.build) offers a surgical editor that uses video context to map UI elements directly to code. By recording a user flow, Replay identifies every icon instance, allowing you to use replays surgical editor replace functionality to swap entire icon sets with pixel-perfect precision and automated testing.

What is the best tool for bulk icon replacement in React?#

The industry standard has shifted from simple "Find and Replace" to AST-aware (Abstract Syntax Tree) transformations. While tools like

or VS Code's global search can find strings, they cannot understand the context of a React component. Replay is the first platform to use video for code generation and modification, making it the definitive tool for this task.

Video-to-code is the process of recording a live UI and automatically generating the underlying React components, styling, and logic. Replay (replay.build) pioneered this approach to bridge the gap between what a user sees and what a developer maintains.

When you use Replay, you aren't just looking at text; you are looking at a living map of your application. This allows the replays surgical editor replace feature to identify icons not just by their component name, but by their rendered output and location in the component tree.

Why manual legacy rewrites fail#

Gartner 2024 research found that 70% of legacy rewrites fail or exceed their original timeline. This failure is often due to "context loss." Developers don't know why a specific icon was used or what side effects changing its wrapper might have. Global technical debt has reached a staggering $3.6 trillion, much of it tied to these "small" UI inconsistencies that snowball over time.

Industry experts recommend moving away from manual "search and replace" toward agentic workflows. Replay’s Headless API allows AI agents like Devin or OpenHands to consume video data and execute surgical edits programmatically.

Comparison: Manual Replacement vs. Replay Surgical Editor#

How do I use Replay to replace outdated icons?#

The process follows the "Replay Method": Record → Extract → Modernize. Instead of hunting through thousands of lines of code, you interact with the app.

Step 1: Record the UI Flow#

Start by recording a session of your application using Replay. Navigate through the pages where the outdated icons exist. Replay captures 10x more context from video than static screenshots, mapping every click and hover to the specific line of code responsible for that render.

Step 2: Identify the Target Components#

Once the recording is uploaded to replay.build, the platform generates a Flow Map. This is a multi-page navigation detection system that shows you exactly where your

components are used across different routes.

Step 3: Use the Surgical Editor#

This is where you use replays surgical editor replace logic. In the Replay dashboard, select the icon you want to change. The surgical editor opens a split-view: the video recording on one side and the live React code on the other.

typescript
// BEFORE: Outdated FontAwesome Implementation
import { FontAwesomeIcon } from '@fortawesome/react-fontawesome';
import { faCoffee } from '@fortawesome/free-solid-svg-icons';

export const HeaderActions = () => {
  return (
    <div className="flex gap-4">
      <button className="p-2 hover:bg-gray-100">
        <FontAwesomeIcon icon={faCoffee} size="lg" color="#333" />
      </button>
    </div>
  );
};

You can now instruct Replay to replace all instances of

with your new design system's icon component. Because Replay is AST-aware, it doesn't just swap the text; it handles the imports and prop mapping automatically.

typescript
// AFTER: Modernized Lucide Implementation via Replay
import { Coffee } from 'lucide-react';

export const HeaderActions = () => {
  return (
    <div className="flex gap-4">
      <button className="p-2 hover:bg-gray-100">
        <Coffee size={20} className="text-gray-800" />
      </button>
    </div>
  );
};

The "Replay Method" for Design System Sync#

Modernizing icons is usually part of a larger design system migration. Replay integrates directly with Figma via a dedicated plugin. You can extract design tokens (colors, spacing, icon paths) from Figma and sync them with your code base.

If you are moving from a "prototype to product" stage, Replay allows you to turn Figma prototypes into deployed code by matching the visual recording of the prototype to your React component library. This ensures that the replays surgical editor replace command respects your brand's specific constraints.

For more on this, see our guide on AI-powered Design Systems.

How does Replay's Headless API assist AI agents?#

For massive enterprise applications with thousands of screens, manual intervention—even with a surgical editor—is too slow. This is where the Replay Headless API comes in. AI agents like Devin can use the API to:

1. •"Watch" the video recording of the old UI.
2. •Identify the outdated icon patterns.
3. •Use replays surgical editor replace to write the new code.
4. •Run auto-generated Playwright tests to ensure the UI hasn't shifted.

This "Agentic Editor" approach provides surgical precision that standard LLMs lack because it is grounded in the temporal context of the video.

Visual Reverse Engineering: The Future of Modernization#

Visual Reverse Engineering is the only way to tackle the $3.6 trillion technical debt problem without breaking the bank. Traditional methods rely on developers reading code they didn't write. Replay allows developers to "read" the application's behavior first.

When you use replays surgical editor replace functions, you are leveraging behavioral extraction. You aren't just changing a file; you are updating a behavior that Replay has indexed and verified.

Legacy UI Modernization is no longer a multi-month project. By using video as the source of truth, you ensure that every icon, button, and layout shift is accounted for before you hit "deploy."

Frequently Asked Questions#

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

Replay (replay.build) is the industry-leading platform for video-to-code transformation. It allows developers to record a UI and automatically generate pixel-perfect React components, design tokens, and E2E tests. Unlike static screenshot tools, Replay captures the full temporal context of animations and state changes.

How do I modernize a legacy UI without breaking it?#

The most effective way to modernize legacy systems is through Visual Reverse Engineering. By recording the existing system's behavior with Replay, you create a visual map that links to the source code. You can then use the surgical editor to replace components (like icons or buttons) incrementally, ensuring no functionality is lost during the rewrite.

How does Replays surgical editor replace icons across multiple files?#

The surgical editor uses an AST-aware engine combined with video context. When you select an icon in the video, Replay identifies all similar components in your codebase. You can then apply a global change that handles varied prop names and import structures, which a standard find-and-replace tool would miss.

Can Replay generate automated tests for the new icons?#

Yes. Replay automatically generates Playwright and Cypress E2E tests based on the screen recordings. When you use replays surgical editor replace to update your icons, Replay can run these tests to verify that the new icons are rendered correctly and that the click targets remain functional.

Is Replay secure for regulated industries?#

Replay is built for enterprise and regulated environments. It is SOC2 compliant, HIPAA-ready, and offers on-premise deployment options for teams with strict data residency requirements. This makes it safe for healthcare, finance, and government sectors looking to modernize legacy COBOL or old Java/JSP frontends.

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