Back to Blog
January 5, 20267 min readReplay AI vs

Replay AI vs Locofy: AI tools compared with testing UI videos to increase performance

R
Replay Team
Developer Advocates

TL;DR: Replay AI leverages video analysis to reconstruct UI code based on observed user behavior, offering a more accurate and functional output compared to screenshot-based tools like Locofy.

The dream of automatically generating code from visual inputs has been around for years. While screenshot-to-code tools have made some progress, they often fall short in capturing the nuances of user interaction and application logic. This is where Replay AI steps in, taking a revolutionary approach by using video as the primary source of truth. Let's dive into a head-to-head comparison of Replay AI versus Locofy, focusing on their capabilities and performance in reconstructing UI from videos.

Understanding the Limitations of Screenshot-to-Code#

Traditional screenshot-to-code tools, like Locofy, analyze static images to generate UI code. This approach has inherent limitations:

  • Lack of Context: Screenshots don't capture user interactions, animations, or dynamic data changes. The tool only sees a single frame in time.
  • Static Representation: UI elements are interpreted as static components, ignoring their interactive behavior.
  • Inability to Replicate Complex Flows: Multi-step user flows and complex state management are impossible to infer from a single screenshot.

These limitations often result in code that requires significant manual rework, negating the promised time savings.

Replay AI: Behavior-Driven Reconstruction#

Replay AI addresses these limitations by analyzing video of user interactions. This "Behavior-Driven Reconstruction" approach allows Replay to:

  • Understand User Intent: By observing mouse movements, clicks, and form inputs, Replay infers the user's goals and the application's intended behavior.
  • Capture Dynamic States: Video captures state changes, animations, and data updates, leading to a more accurate representation of the UI.
  • Reconstruct Complex Flows: Replay can follow multi-page flows and reconstruct the underlying logic that drives them.

This results in code that is not only visually similar to the original UI but also functional and interactive.

Replay AI vs. Locofy: A Detailed Comparison#

Let's examine a detailed comparison of Replay AI and Locofy across key features:

FeatureLocofyReplay AI
Input TypeScreenshots, Design Files (Figma, Adobe XD)Videos, Screen Recordings
Behavior Analysis
Multi-Page GenerationLimited
Dynamic Content Handling
Code QualityRequires Significant ReworkFunctional, Interactive Code
Learning CurveRelatively EasyModerate (Understanding of Video Analysis Concepts)
Supabase Integration
Style InjectionLimited
Product Flow Maps

As the table shows, Replay AI's video-based approach offers significant advantages in terms of behavior analysis, dynamic content handling, and overall code quality. Locofy, while easier to get started with, falls short in replicating complex user interactions and application logic.

Practical Example: Reconstructing a Simple Form#

Let's consider a simple example: reconstructing a user registration form.

Locofy Approach (Screenshot-Based)#

With Locofy, you would upload a screenshot of the registration form. The tool would identify the input fields and buttons, generating basic HTML and CSS. However, it would lack:

  • Validation Logic: No understanding of required fields, email format validation, or password strength requirements.
  • Submission Handling: No code to handle form submission and data persistence.
  • Dynamic Feedback: No implementation of error messages or success notifications.

The generated code would require extensive manual coding to add these essential features.

Replay AI Approach (Video-Based)#

With Replay AI, you would record a video of a user interacting with the registration form. The tool would observe:

  • Field Inputs: The values entered into each field.
  • Validation Errors: The error messages displayed when invalid data is entered.
  • Submission Process: The actions taken after submitting the form.

Based on this analysis, Replay AI would generate code that includes:

  • Input Validation: Client-side validation to ensure data quality.
  • Submission Handling: Code to send the form data to a backend API.
  • Dynamic Feedback: Display of error messages and success notifications.

The generated code would be significantly more complete and functional, requiring less manual rework.

Code Example: Form Submission Handling#

Here's a simplified example of how Replay AI might generate code to handle form submission:

typescript
// TypeScript example of form submission handling generated by Replay AI const handleSubmit = async (event: React.FormEvent<HTMLFormElement>) => { event.preventDefault(); const formData = new FormData(event.currentTarget); const email = formData.get('email'); const password = formData.get('password'); try { const response = await fetch('/api/register', { method: 'POST', headers: { 'Content-Type': 'application/json', }, body: JSON.stringify({ email, password }), }); if (response.ok) { // Handle successful registration alert('Registration successful!'); } else { // Handle registration error const errorData = await response.json(); alert(`Registration failed: ${errorData.message}`); } } catch (error) { console.error('Error during registration:', error); alert('An error occurred during registration.'); } };

This code snippet demonstrates how Replay AI can automatically generate code to handle form submission, error handling, and success notifications based on observed user behavior in the video.

💡 Pro Tip: When recording videos for Replay AI, be sure to showcase both successful and unsuccessful interactions to provide the tool with a comprehensive understanding of the application's behavior.

Addressing Common Concerns#

Some common concerns about video-to-code tools like Replay AI include:

  • Privacy: Video recordings may contain sensitive information. Replay AI addresses this by offering on-premise deployment options and data anonymization features.
  • Accuracy: The accuracy of the generated code depends on the quality of the video and the complexity of the UI. Replay AI uses advanced AI algorithms to minimize errors and provide accurate results.
  • Performance: Video analysis can be computationally intensive. Replay AI is optimized for performance and can process videos quickly and efficiently.

⚠️ Warning: Ensure that you have the necessary permissions and consent before recording videos of user interactions, especially if the videos contain personal or sensitive information.

Step-by-Step Guide: Using Replay AI for UI Reconstruction#

Here's a simplified guide to using Replay AI for UI reconstruction:

Step 1: Record a Video#

Record a video of a user interacting with the UI you want to reconstruct. Be sure to capture all relevant interactions, including clicks, form inputs, and state changes.

Step 2: Upload the Video to Replay AI#

Upload the video to the Replay AI platform.

Step 3: Review the Generated Code#

Replay AI will analyze the video and generate code. Review the generated code to ensure accuracy and completeness.

Step 4: Customize and Integrate the Code#

Customize the generated code to meet your specific requirements. Integrate the code into your existing project.

📝 Note: Replay AI also supports integration with Supabase, allowing you to easily connect your UI to a backend database.

Benefits of Using Replay AI#

  • Faster Development: Automate UI reconstruction and reduce manual coding effort.
  • Improved Accuracy: Capture user behavior and application logic for more accurate results.
  • Enhanced Functionality: Generate code that is not only visually similar but also functional and interactive.
  • Better User Experience: Replicate the intended user experience more accurately.

Frequently Asked Questions#

Is Replay AI free to use?#

Replay AI offers a free tier with limited features and usage. Paid plans are available for more advanced features and higher usage limits.

How is Replay AI different from v0.dev?#

While both aim to generate code, v0.dev relies on text prompts and predefined components. Replay AI analyzes video to understand user behavior and reconstruct the UI based on observed interactions, leading to more accurate and functional code. Replay focuses on capturing the "how" and "why" of the UI, not just the "what."

What types of videos work best with Replay AI?#

Clear, well-lit videos with minimal camera shake work best. Ensure that the video captures all relevant user interactions and state changes.

What frameworks does Replay AI support?#

Replay AI currently supports React, Vue, and Angular, with plans to support more frameworks in the future.


Ready to try behavior-driven code generation? Get started with Replay - transform any video into working code in seconds.

Ready to try Replay?

Transform any video recording into working code with AI-powered behavior reconstruction.

Launch Replay Free