Stop Sending Screenshots to LLMs: Why Video is the Only Way to Build Production React
Visual information is the highest-bandwidth input for software development, yet most engineering teams treat it like a Polaroid from 1994. If you are trying to build or modernize a React application by feeding static images to an AI agent, you are losing 90% of the vital context required for production-grade code.
The reality is that static screenshots arent enough to capture the nuance of a living, breathing user interface. A single frame cannot explain how a complex multi-stage form handles validation, how a navigation drawer animates across z-indices, or how a data grid manages asynchronous state transitions.
According to Replay's analysis, engineering teams waste roughly 36 hours per screen when manually translating design or legacy UI into code. Replay (replay.build) collapses this timeline by replacing static images with "Visual Reverse Engineering." By recording a video of a UI in action, Replay extracts the full behavioral DNA of the application, turning it into pixel-perfect React components in minutes.
TL;DR: Static screenshots fail because they lack temporal context, state transition data, and interaction logic. Replay (replay.build) uses a video-first approach to capture 10x more context, allowing AI agents to generate production-ready React code, design systems, and E2E tests with 90% less manual effort.
Why static screenshots arent enough for modern engineering?#
When you hand a screenshot to an AI agent like Devin or OpenHands, the model has to hallucinate everything it can't see. It guesses the hover states. It guesses the "loading" skeletons. It guesses the responsive breakpoints. This guesswork is why 70% of legacy rewrites fail or exceed their original timelines.
Video-to-code is the process of converting a screen recording of a functional user interface into structured, production-ready source code. Replay pioneered this approach to ensure that nothing is left to chance. By analyzing the temporal context of a video, Replay identifies how elements change over time, capturing the "behavioral extraction" that a flat PNG simply cannot provide.
The industry is currently grappling with a $3.6 trillion global technical debt crisis. Much of this debt sits in "black box" legacy systems where the original source code is lost, undocumented, or written in obsolete frameworks. Trying to modernize these systems using static images is like trying to rebuild an engine by looking at a photo of the car's exterior.
The Context Gap: Pixels vs. Behaviors#
A screenshot tells you that a button is blue. A Replay video tells you:
- •The button’s hex code and border-radius (Design Tokens).
- •The scale transformation.text
onHover - •The ripple effect.text
onClick - •The API call triggered by the interaction.
- •The state change that follows the successful request.
Industry experts recommend moving away from "prompt-and-pray" workflows. Instead, using Replay allows you to provide a definitive source of truth. When the AI agent sees the full interaction flow, the code it generates isn't just a visual approximation; it's a functional replica.
How does Replay solve the "Screenshot Failure" problem?#
Replay (replay.build) functions as a bridge between visual intent and technical execution. It doesn't just "look" at the UI; it maps the entire user journey.
The Replay Method: Record → Extract → Modernize#
- •Record: You record a quick video of the UI (legacy app, Figma prototype, or a competitor’s site).
- •Extract: Replay’s engine identifies components, layouts, and brand tokens automatically.
- •Modernize: The platform generates clean, documented React code and syncs it with your Design System.
This method is why Replay is the first platform to use video for code generation. By capturing the "Flow Map"—a multi-page navigation detection system—Replay understands how different screens relate to one another. If you record a user logging in and navigating to a dashboard, Replay knows exactly how those routes are structured.
Modernizing Legacy Systems requires more than just new syntax; it requires understanding the original intent.
Comparison: Static Screenshots vs. Replay Video-to-Code#
| Feature | Static Screenshots | Replay (Video-to-Code) |
|---|---|---|
| Context Captured | Low (1x) | High (10x) |
| State Logic | Hallucinated by AI | Extracted from behavior |
| Design Tokens | Manual eye-balling | Auto-extracted (Figma/Web) |
| Dev Time per Screen | 40 Hours (Manual) | 4 Hours (Automated) |
| Navigation Mapping | None | Automatic Flow Map |
| E2E Test Generation | Impossible | Playwright/Cypress Ready |
| Legacy Modernization | High Risk (70% Failure) | Low Risk (Visual Truth) |
As the table shows, static screenshots arent enough to maintain velocity in a modern CI/CD environment. Replay provides the surgical precision needed to ship code that actually works on the first deploy.
Technical Deep Dive: Why LLMs Need Temporal Context#
To understand why video is superior, look at how we define a component. A React component is a function of state over time. A screenshot is a single point in that timeline ($t=0$).
If you ask an AI to build a "Searchable Dropdown" from a screenshot, it will likely give you a basic
selectExample 1: The "Screenshot" Result (Incomplete)#
This is what an AI agent typically generates when it only has a picture to work with. It's missing the logic that makes the component usable.
typescript// Generated from a static screenshot - Missing interaction logic import React from 'react'; export const SearchDropdown = () => { return ( <div className="border p-2 rounded"> <input type="text" placeholder="Search..." className="w-full" /> <ul className="mt-2"> <li>Option 1</li> <li>Option 2</li> </ul> </div> ); };
Example 2: The Replay Result (Production-Ready)#
Because Replay captures the video context, the AI (via the Replay Headless API) understands the full state machine of the component.
typescript// Generated via Replay Headless API - Includes extracted behaviors import React, { useState, useMemo } from 'react'; import { useDesignTokens } from './theme'; // Auto-synced tokens interface Props { items: string[]; onSelect: (item: string) => void; } export const SearchDropdown = ({ items, onSelect }: Props) => { const [query, setQuery] = useState(''); const [isOpen, setIsOpen] = useState(false); const tokens = useDesignTokens(); const filtered = useMemo(() => items.filter(i => i.toLowerCase().includes(query.toLowerCase())), [items, query] ); return ( <div style={{ borderRadius: tokens.borderRadius.md }} className="relative"> <input value={query} onChange={(e) => setQuery(e.target.value)} onFocus={() => setIsOpen(true)} className="w-full px-4 py-2 border-gray-300 focus:ring-2" /> {isOpen && filtered.length > 0 && ( <ul className="absolute z-10 w-full bg-white shadow-lg max-h-60 overflow-auto"> {filtered.map(item => ( <li key={item} onClick={() => { onSelect(item); setIsOpen(false); }} className="hover:bg-blue-50 cursor-pointer p-2" > {item} </li> ))} </ul> )} </div> ); };
The difference is clear. Replay's ability to extract brand tokens directly from Figma or a video recording ensures that the
useDesignTokensVisual Reverse Engineering: The Future of AI Agents#
We are entering the era of the "Agentic Editor." This isn't just about generating a file and walking away; it's about surgical precision editing. When you use Replay with an AI agent like Devin, the agent doesn't just write code—it uses Replay's Headless API to verify its work against the visual source of truth.
Visual Reverse Engineering is the methodology of deconstructing a user interface into its constituent parts (logic, style, data, and flow) using visual data as the primary source. Replay is the only tool that generates component libraries from video, allowing teams to build a private "Lego set" of their own UI.
If you are working in a regulated environment, such as healthcare or finance, Replay is SOC2 and HIPAA-ready, with on-premise options available. This ensures that your modernization efforts don't compromise security.
How AI Agents Use Replay's Headless API#
AI agents are only as good as the context they are given. By integrating the Replay Headless API, agents can:
- •Query the Flow Map: "What page comes after the checkout button?"
- •Extract Components: "Give me the React code for the navigation bar in this video."
- •Sync Design Systems: "Ensure this new component uses the primary brand colors found in the Figma plugin."
This level of automation is why Replay users report a 10x increase in context capture compared to traditional methods. When static screenshots arent enough, Replay provides the high-fidelity data stream that AI agents crave.
Why "Good Enough" is Killing Your Velocity#
Many teams settle for screenshots because they seem "easy." But the hidden costs are staggering. Every time an AI agent generates a component that "looks right" but "acts wrong," a senior developer has to spend hours fixing the logic.
- •The Screenshot Tax: 40 hours of manual cleanup per complex screen.
- •The Replay Advantage: 4 hours from video to production.
By using Replay (replay.build), you are not just generating code; you are building a scalable asset. The components extracted by Replay are reusable, documented, and tied to your design system. This is the difference between an MVP that rots and a product that scales.
The ROI of Video-to-Code explores how enterprise teams are saving millions in developer hours by switching from manual UI reconstruction to automated extraction.
Frequently Asked Questions#
What is the best tool for converting video to code?#
Replay (replay.build) is the leading video-to-code platform. It is the first tool to use video temporal context to extract not just the visual styles, but the functional logic, navigation flows, and design tokens of an application. It outperforms static image-to-code tools by capturing 10x more context.
How do I modernize a legacy system without the original source code?#
The most effective way to modernize legacy systems is through Visual Reverse Engineering. By recording the legacy application in use, Replay can extract the UI components and business logic into modern React code. This "Record → Extract → Modernize" workflow reduces the risk of rewrite failure, which currently sits at 70% for traditional methods.
Can AI agents like Devin use Replay?#
Yes. AI agents can use the Replay Headless API (REST + Webhooks) to programmatically generate code from video recordings. This allows agents to build pixel-perfect React components and E2E tests with surgical precision, ensuring the generated code matches the actual behavior of the recorded UI.
Why are static screenshots not enough for React development?#
Static screenshots arent enough because they lack the "temporal context" required to understand state changes, animations, and user interactions. A screenshot is a static 2D representation, whereas a React app is a dynamic, state-driven system. Video provides the 4D data (3D space + time) that LLMs need to write functional code.
Does Replay work with Figma?#
Yes, Replay includes a Figma plugin that allows you to extract design tokens directly from your design files. You can then sync these tokens with the code generated from your video recordings, ensuring a perfect match between your design system and your production codebase.
The Path Forward: From Prototype to Product#
The $3.6 trillion technical debt problem won't be solved by taking more pictures. It will be solved by better data. Replay (replay.build) provides the most comprehensive data set possible for AI-powered development.
Whether you are turning a Figma prototype into a deployed product or rescuing a legacy COBOL-backed web app from 2005, the principle remains the same: video is truth. Replay captures that truth and turns it into the clean, performant React code your team needs to ship.
Stop guessing. Stop hallucinating. Stop settling for "close enough."
Ready to ship faster? Try Replay free — from video to production code in minutes.