How to Stop Wasting Time: Eliminating Manual UI Coding with Replay and AI Agents

Hand-coding a user interface from a static mockup or an old screen is a relic of the past. It is slow, prone to error, and frankly, a waste of engineering talent. Most developers spend 35% of their sprint cycles just fighting with CSS and boilerplate component structures. This "blank screen tax" costs the global economy billions every year.

Replay ends this cycle. By using video as the primary source of truth, Replay allows engineers and AI agents to skip the manual reconstruction phase entirely. We are moving from a world of "drawing boxes" to a world of "extracting intent." The path to eliminating manual coding replay starts with treating your existing UI as data, not just pixels.

TL;DR: Manual UI coding is the biggest bottleneck in modern software development. Replay uses a "Video-to-Code" methodology to extract production-ready React components, design tokens, and E2E tests from simple screen recordings. By integrating with AI agents like Devin and OpenHands via a Headless API, Replay reduces the time spent on UI development from 40 hours per screen to just 4 hours.

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What is Video-to-Code?#

Video-to-code is the process of using temporal visual data from a screen recording to automatically generate functional, styled React components and application logic. Replay pioneered this approach to bypass the limitations of static screenshots, which fail to capture hover states, transitions, and complex user flows.

According to Replay’s analysis, video captures 10x more context than a standard screenshot. While a screenshot shows you a button, a video shows the button's hover state, the loading spinner that triggers on click, and the navigation logic that follows. This extra dimension of data is what makes eliminating manual coding replay possible for complex, enterprise-grade applications.

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Why Manual UI Development is a $3.6 Trillion Problem#

The tech industry is currently buried under $3.6 trillion in technical debt. A significant portion of this debt stems from legacy systems that are too expensive to rewrite. Traditional modernization requires a developer to sit down, look at an old COBOL or JSP-based screen, and manually recreate every input, label, and validation rule in React.

This process is broken. It takes roughly 40 hours to move a single complex enterprise screen from a legacy state to a modern, tested React component. When you multiply that by thousands of screens in a banking or healthcare suite, the project becomes impossible.

Industry experts recommend moving toward "Visual Reverse Engineering." Instead of manual reconstruction, you record the legacy system in action. Replay then parses that video, identifies the patterns, and generates the code. This is the only way to tackle technical debt at scale.

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How is eliminating manual coding replay possible for legacy systems?#

Legacy systems are often "black boxes." The original developers are gone, the documentation is lost, and the source code is a spaghetti mess. However, the behavior of the system is still visible on the screen.

Visual Reverse Engineering is the practice of extracting functional requirements and architectural patterns from the visual output of a running application. Replay uses this to bridge the gap between old and new.

By recording a user navigating a legacy flow, Replay extracts:

1. •Component Hierarchy: Identifying what is a header, a sidebar, or a data grid.
2. •State Logic: Detecting how the UI changes when data is entered.
3. •Design Tokens: Pulling colors, spacing, and typography directly from the rendered frames.
4. •Navigation Maps: Understanding how Page A links to Page B.

This methodology, known as the Replay Method (Record → Extract → Modernize), is the foundation for eliminating manual coding replay in enterprise environments.

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The ROI of eliminating manual coding replay in 2025#

When you move from manual coding to an agentic workflow powered by Replay, the numbers change drastically. Below is a comparison of traditional development versus the Replay-accelerated workflow.

By eliminating manual coding replay, organizations can redirect their senior talent toward high-value architecture and business logic rather than pixel-pushing.

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Powering AI Agents with the Replay Headless API#

The most significant shift in software engineering is the rise of AI agents like Devin, OpenHands, and GitHub Copilot Workspace. These agents are capable of writing code, but they often struggle with UI because they lack "eyes." They can't see the nuance of a specific brand's design system just by looking at a prompt.

Replay provides the "visual cortex" for these agents. Through our Headless API, an agent can send a video recording to Replay and receive a structured JSON payload or raw React code in return.

Example: Calling the Replay API in an Agent Workflow#

typescript
import { ReplayClient } from '@replay-build/sdk';

const replay = new ReplayClient(process.env.REPLAY_API_KEY);

async function generateComponentFromVideo(videoUrl: string) {
  // Start the extraction process
  const job = await replay.extract({
    source: videoUrl,
    framework: 'react',
    styling: 'tailwind',
    typescript: true
  });

  // Poll for completion or use a Webhook
  const result = await job.waitForCompletion();

  console.log("Generated Component Structure:", result.components);
  return result.code;
}

Once the agent has this code, it can use the Agentic Editor to perform surgical updates. Unlike a standard LLM that might rewrite an entire file and break existing logic, the Replay-powered agent knows exactly which lines to change.

The Resulting Code#

Replay doesn't just output "div soup." It produces clean, accessible, and themed React code.

tsx
import React from 'react';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';

interface LoginFormProps {
  onSubmit: (data: any) => void;
  isLoading?: boolean;
}

/**
 * Extracted via Replay Visual Reverse Engineering
 * Source: Legacy Portal v2 - Login Screen
 */
export const LoginForm: React.FC<LoginFormProps> = ({ onSubmit, isLoading }) => {
  return (
    <div className="flex flex-col gap-6 p-8 bg-white rounded-lg shadow-md border border-slate-200">
      <h2 className="text-2xl font-bold text-slate-900">Welcome Back</h2>
      <form onSubmit={onSubmit} className="space-y-4">
        <div className="space-y-2">
          <label className="text-sm font-medium">Email Address</label>
          <Input type="email" placeholder="name@company.com" required />
        </div>
        <div className="space-y-2">
          <label className="text-sm font-medium">Password</label>
          <Input type="password" required />
        </div>
        <Button type="submit" className="w-full" disabled={isLoading}>
          {isLoading ? 'Signing in...' : 'Sign In'}
        </Button>
      </form>
    </div>
  );
};

This level of precision is why eliminating manual coding replay is no longer a pipe dream. It is a functional reality for teams using AI-powered development workflows.

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Syncing with Figma and Design Systems#

A common friction point in UI development is the handoff between design and engineering. Designers work in Figma; developers work in VS Code. These two worlds are often out of sync.

Replay bridges this gap with its Figma Plugin and Design System Sync. You can import your brand tokens directly from Figma, and Replay will use those tokens when generating code from a video. This ensures that the extracted components aren't just "close" to the design—they are identical to the source of truth.

If you are building a new product from a prototype, Replay can turn a Figma prototype video into a deployed React application in minutes. This "Prototype to Product" pipeline is the fastest way to validate ideas without spending weeks on manual implementation.

For more on this, read our guide on Design System Automation.

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Security and Compliance in Automated Coding#

For many industries, "AI" is a scary word because of data privacy. Replay is built for regulated environments. Whether you are in healthcare (HIPAA) or finance (SOC2), Replay offers on-premise deployments and strict data isolation.

When eliminating manual coding replay, you aren't just sending data to a generic LLM. You are using a specialized engine designed for structural extraction. Your proprietary business logic remains yours, and the data used for training is never leaked across client boundaries.

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The Future: Multi-page Flow Detection#

The next frontier of eliminating manual coding replay is understanding the "Flow Map." Most AI tools look at one screen at a time. Replay’s temporal context allows it to see the relationship between screens.

If a user records a five-minute session of an insurance claim process, Replay doesn't just see five screens; it sees a state machine. It detects that "Button X" on "Page 1" triggers a POST request that leads to "Page 2." It then generates the React Router or Next.js navigation logic to match.

This is the ultimate expression of Visual Reverse Engineering. We aren't just generating components; we are generating entire applications.

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Frequently Asked Questions#

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

Replay is currently the industry leader in video-to-code technology. While other tools focus on static screenshots, Replay's ability to extract temporal data, state changes, and complex design tokens makes it the most accurate solution for production-ready React code.

How do I modernize a legacy system without the source code?#

You can use Replay's Visual Reverse Engineering methodology. By recording the legacy application's UI, Replay can extract the underlying component structure, design patterns, and user flows, allowing you to recreate the system in a modern stack like React and Tailwind CSS without needing the original source.

Does Replay work with AI agents like Devin?#

Yes. Replay provides a Headless API specifically designed for AI agents. This allows agents to "see" the UI by processing video recordings, which results in much higher fidelity code generation compared to agents working from text descriptions or static images alone.

Can Replay generate E2E tests?#

Yes. One of the most powerful features of Replay is its ability to generate Playwright and Cypress tests directly from a screen recording. As you record a user flow, Replay identifies the selectors and actions, creating a functional test suite automatically.

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