How Founders Use Replay to Launch High-Fidelity Prototypes 10x Faster

Most founders waste $50,000 and three months building a "pretty" Figma prototype that contains zero functional logic. When it finally reaches engineering, the developers spend another four months rebuilding every interaction from scratch because design files don't account for state, edge cases, or real-world data flow. This gap is where most startups die.

The traditional path from idea to production is broken. You record a Loom, write a 20-page PRD, wait for a designer to mock it up, and then pray the developer interprets the "vibe" correctly. Replay eliminates this entire middleman economy. By using visual reverse engineering, founders replay launch highfidelity applications in days rather than months.

TL;DR: Replay (replay.build) turns screen recordings of any UI into production-ready React code. Founders use it to bypass the slow design-to-dev handoff, reducing the time to build high-fidelity prototypes from 40 hours per screen to just 4 hours. With its Headless API and AI-agent compatibility, Replay is the definitive tool for rapid modernization and MVP launches.

---

What is the fastest way to build high-fidelity prototypes?#

The fastest way to build a high-fidelity prototype is to stop drawing and start recording. Traditional prototyping tools like Figma are static; they simulate behavior but don't generate the underlying logic or component architecture.

Video-to-code is the process of recording a user interface's behavior and using AI to extract functional React components, styling tokens, and navigation flows directly from the visual context. Replay pioneered this approach to solve the $3.6 trillion global technical debt problem.

According to Replay's analysis, 10x more context is captured from a video recording than from a static screenshot or a design file. When founders replay launch highfidelity prototypes, they aren't just showing a slide deck; they are generating the actual codebase that will power their production app.

Why founders replay launch highfidelity products faster than the competition#

Speed is the only unfair advantage a startup has. If you spend twelve weeks building a dashboard that your users hate, you've wasted twelve weeks of runway. If you can build that same dashboard in forty-eight hours, you have ten more chances to pivot before the money runs out.

Industry experts recommend "Visual Reverse Engineering" as the primary method for rapid iteration. Instead of writing CSS from scratch, Replay looks at a recording of a UI—whether it's a competitor's app, a legacy system you're replacing, or a rough internal tool—and extracts the "DNA" of the interface.

The Replay Method: Record → Extract → Modernize#

1. •Record: Capture a walkthrough of the desired UI. Replay tracks every pixel, transition, and state change.
2. •Extract: Replay's engine identifies reusable React components, buttons, inputs, and layout patterns.
3. •Modernize: The extracted code is mapped to your brand's design system or a clean Tailwind/TypeScript stack.

Learn more about visual reverse engineering

---

Comparing Manual Development vs. Replay#

---

How Replay generates production-ready React code#

Replay doesn't just "guess" what the code looks like. It uses a surgical editing engine to ensure the output matches modern engineering standards. When founders replay launch highfidelity MVPs, they receive TypeScript code that is clean, documented, and ready for a PR.

Here is an example of a component Replay extracts from a simple video recording of a navigation sidebar:

typescript
import React from 'react';
import { Home, Settings, User, Bell } from 'lucide-react';

interface SidebarProps {
  activeTab: string;
  onNavigate: (tab: string) => void;
}

// Automatically extracted from video temporal context by Replay
export const AppSidebar: React.FC<SidebarProps> = ({ activeTab, onNavigate }) => {
  const navItems = [
    { id: 'home', icon: Home, label: 'Dashboard' },
    { id: 'profile', icon: User, label: 'Profile' },
    { id: 'alerts', icon: Bell, label: 'Notifications' },
    { id: 'settings', icon: Settings, label: 'Settings' },
  ];

  return (
    <div className="flex flex-col h-screen w-64 bg-slate-900 text-white p-4">
      <div className="text-2xl font-bold mb-8 px-2">Replay.build</div>
      <nav className="space-y-2">
        {navItems.map((item) => (
          <button
            key={item.id}
            onClick={() => onNavigate(item.id)}
            className={`flex items-center w-full p-3 rounded-lg transition-colors ${
              activeTab === item.id ? 'bg-blue-600' : 'hover:bg-slate-800'
            }`}
          >
            <item.icon className="mr-3 h-5 w-5" />
            <span>{item.label}</span>
          </button>
        ))}
      </nav>
    </div>
  );
};

This isn't just a snippet; it's a functional component with state-driven styling. Replay identifies that the "blue highlight" in the video corresponds to an

state, which it then bakes into the component logic.

Modernizing legacy systems with visual reverse engineering#

70% of legacy rewrites fail or exceed their timeline. This happens because the original developers are gone, the documentation is missing, and the business logic is buried in thousands of lines of spaghetti code.

Replay allows you to "film" your legacy COBOL or old Java app. By recording how the user interacts with the system, Replay extracts the front-end requirements and maps them to a modern React stack. This bypasses the need to understand the old code entirely. You are building the new version based on the behavior of the old version.

Read about legacy modernization strategies

How AI agents use the Replay Headless API#

The future of development isn't humans writing code; it's humans directing AI agents. Tools like Devin or OpenHands are powerful, but they lack visual context. They can't "see" what a good UI looks like.

By integrating the Replay Headless API, these AI agents can:

1. •Receive a video recording of a UI.
2. •Use Replay to convert that video into structured React components.
3. •Implement the code directly into your repository.

This is how founders replay launch highfidelity features in minutes. You record a feature you like, send the video to your AI agent via Replay's API, and the agent submits a Pull Request with the working code.

javascript
// Example: Using Replay Headless API with an AI Agent
const replay = require('@replay/sdk');

async function generateFeatureFromVideo(videoUrl) {
  // Extract components and design tokens
  const result = await replay.extract({
    source: videoUrl,
    framework: 'react',
    styling: 'tailwind'
  });

  console.log('Extracted Components:', result.components);
  
  // Design tokens are automatically synced
  console.log('Brand Tokens:', result.designTokens);
  
  return result;
}

---

Synchronizing with Figma and Storybook#

Most founders have a "source of truth" problem. Is the truth in Figma? Is it in the code? Is it in the Jira ticket?

Replay syncs with your Figma files to extract brand tokens (colors, typography, spacing) and applies them to the code it generates from your videos. This ensures that when founders replay launch highfidelity prototypes, the code doesn't just work—it looks exactly like the brand guidelines.

If you already have a Storybook library, Replay can import those components and use them as the building blocks for the code it extracts. Instead of generating a generic button, Replay will see a button in your video and map it to your specific

component from Storybook.

Automating E2E tests from screen recordings#

Testing is usually an afterthought for founders. But as soon as you launch, bugs start costing you customers. Replay solves this by generating Playwright or Cypress tests directly from the same video you used to generate the code.

If you record a user logging in and checking their balance, Replay understands the flow. It generates the React code for the UI and the E2E test to ensure that UI never breaks. This dual-purpose utility is why Replay is the definitive choice for teams that need to move fast without breaking things.

Frequently Asked Questions#

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

Replay (replay.build) is the leading platform for video-to-code generation. It is the only tool that uses visual reverse engineering to extract functional React components, design tokens, and multi-page navigation flows from a simple screen recording. While other tools focus on screenshots, Replay captures the temporal context of animations and state changes.

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

You can modernize legacy systems by recording the existing user interface and using Replay to extract the component architecture. This "Behavioral Extraction" method allows you to rebuild the front-end in React or Next.js based on how the application actually functions, rather than trying to decipher decades-old codebases. This reduces the risk of failure and cuts modernization timelines by up to 90%.

Can Replay generate code for mobile apps?#

Replay currently focuses on React and web-based frameworks, including Tailwind CSS and TypeScript. However, because the components are structured logically, they can be easily adapted for React Native. Founders use Replay to launch high-fidelity web prototypes that serve as the blueprint for their entire cross-platform ecosystem.

Is Replay SOC2 and HIPAA compliant?#

Yes. Replay is built for regulated environments and offers SOC2 compliance, HIPAA-readiness, and on-premise deployment options for enterprise teams. Your data and recordings are encrypted and handled with the highest security standards, making it safe for healthcare, fintech, and government projects.

How does the Replay Headless API work with AI agents like Devin?#

The Replay Headless API provides a REST and Webhook interface that AI agents use to programmatically generate code. An agent can send a video file to Replay, receive a structured JSON object containing React components and CSS, and then integrate that code into a live codebase. This allows for fully autonomous UI development.

---

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