TL;DR: Replay's behavior-driven reconstruction excels at accurately rendering custom fonts from video, unlike Lovable.dev's screenshot-based approach, offering superior fidelity and maintainability.

The year is 2026. AI code generation tools are commonplace, but the devil is in the details. One recurring challenge? Accurately reproducing custom fonts from existing UIs, especially when the source is a video recording showcasing user interaction. Today, we're pitting Replay against Lovable.dev, two leading AI-powered code generation platforms, focusing specifically on their ability to handle custom fonts extracted from video input.

The Font Fidelity Problem#

Many AI code generation tools rely on static screenshots. This approach falls apart when dealing with custom fonts. Why? Screenshots provide pixel-level data, but lack semantic understanding. The AI sees a shape, not a character tied to a specific font family. This leads to incorrect font rendering, layout issues, and a generally unprofessional look.

Lovable.dev, while powerful, primarily uses screenshot analysis. This inherent limitation impacts its ability to accurately reproduce UIs with custom fonts. It may guess at the font or simply render text using a default system font, losing the original design's integrity.

Replay takes a different approach.

Replay: Behavior-Driven Reconstruction#

Replay analyzes video – not just screenshots. This "Behavior-Driven Reconstruction" allows it to understand the intent behind the UI. By tracking mouse movements, clicks, and text input, Replay can infer the underlying UI structure and, crucially, identify custom fonts with greater accuracy. It analyzes the video to understand the underlying CSS and font declarations.

How Replay Handles Custom Fonts#

Replay tackles the custom font challenge in three key ways:

•Font Detection: Using advanced video analysis, Replay identifies potential custom fonts based on visual characteristics and context (e.g., CSS class names, font-family declarations in the surrounding code).
•Web Font Integration: Replay attempts to locate the font on popular web font services (Google Fonts, Adobe Fonts, etc.). If found, it automatically includes the necessary
text
<link>
tags in the generated HTML.
•Font Embedding: If the font is not publicly available, Replay can extract the font file (e.g.,
text
.woff
,
text
.ttf
) directly from the video (if embedded within the UI) or suggest manual embedding.

Step 1: Video Upload and Analysis#

First, upload your video to Replay. Replay processes the video, identifying UI elements, user interactions, and potential custom fonts.

Step 2: Font Identification and Suggestion#

Replay highlights potential custom fonts it has detected and suggests possible matches from web font services. You can manually confirm or correct these suggestions.

Step 3: Code Generation#

Replay generates clean, semantic code that accurately reproduces the UI, including the correct font declarations.

html
<!DOCTYPE html>
<html>
<head>
  <title>Reconstructed UI</title>
  <link rel="stylesheet" href="style.css">
  <link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Oswald:wght@400;700&display=swap">
</head>
<body>
  <div class="container">
    <h1 class="title">Welcome to Our Website</h1>
    <p class="description">This website uses the Oswald font for a modern look.</p>
  </div>
</body>
</html>

css
/* style.css */
.container {
  font-family: 'Oswald', sans-serif;
  text-align: center;
  padding: 20px;
}

.title {
  font-weight: 700;
  font-size: 2.5em;
}

.description {
  font-weight: 400;
  font-size: 1.2em;
}

💡 Pro Tip: If Replay cannot automatically identify a font, it will provide a warning and suggest manually adding the font file and CSS rules.

Replay vs. Lovable.dev: A Head-to-Head Comparison#

Let's break down the key differences in a side-by-side comparison:

Feature	Lovable.dev	Replay
Input Source	Screenshots	Video
Custom Font Detection	Limited	Excellent
Web Font Integration	Basic	Advanced
Behavior Analysis	❌	✅
Font Embedding Suggestion	❌	✅
Accuracy	Good (for standard fonts)	Excellent (including custom fonts)
Code Maintainability	Moderate	High

As you can see, Replay's video-based approach gives it a significant advantage in handling custom fonts.

⚠️ Warning: Manually embedding fonts can increase the size of your website. Optimize your fonts for web use to ensure fast loading times.

Real-World Scenario: Reconstructing a Landing Page#

Imagine you have a video recording of a user interacting with a landing page that uses a unique, self-hosted font called "AcmeGothic."

Lovable.dev, analyzing screenshots from the video, might render the text in a similar-looking system font like Arial or Helvetica. The overall look and feel would be compromised.

Replay, on the other hand, would:

•Detect the presence of a non-standard font.
•Attempt to identify "AcmeGothic" online.
•If unsuccessful, it would alert you to the need to manually include the font file.
•Generate code with the correct
text
font-family
declaration:

css
body {
  font-family: 'AcmeGothic', sans-serif;
}

@font-face {
    font-family: 'AcmeGothic';
    src: url('fonts/AcmeGothic.woff2') format('woff2'),
         url('fonts/AcmeGothic.woff') format('woff');
    font-weight: normal;
    font-style: normal;
}

This ensures the reconstructed landing page accurately reflects the original design.

Beyond Fonts: The Power of Behavior#

Replay's advantage extends beyond just font handling. By understanding user behavior, Replay can:

•Generate multi-page applications: Reconstruct entire user flows, not just single screens.
•Integrate with backend services: Automatically connect the UI to your Supabase database.
•Inject custom styles: Apply your existing design system to the generated code.
•Create product flow maps: Visualize the user journey through the application.

Lovable.dev, limited by its screenshot-based approach, struggles to replicate these dynamic aspects of a UI.

📝 Note: Replay is constantly evolving. Future updates will include even more sophisticated font recognition and embedding capabilities.

Frequently Asked Questions#

Is Replay free to use?#

Replay offers a free tier with limited features. Paid plans unlock advanced capabilities, such as multi-page generation and Supabase integration.

How is Replay different from v0.dev?#

While both are AI-powered code generation tools, Replay focuses on reconstructing existing UIs from video, while v0.dev generates new UIs from text prompts. Replay excels at capturing the nuances of existing designs, including custom fonts and user interactions.

Can Replay handle complex animations and transitions?#

Replay can capture basic animations and transitions. More complex animations may require manual adjustments in the generated code.

What file formats does Replay support?#

Replay supports most common video formats, including MP4, MOV, and AVI.

How secure is Replay?#

Replay uses industry-standard security measures to protect your data. All video uploads are encrypted, and your code is stored securely.

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

Replay vs. Lovable.dev (2026): Which AI Handles Custom Fonts from Video Better?