# Thumbnail Labs

> Free YouTube thumbnail tester and preview tool at [Thumbnail Labs](https://thumbnaillabs.com)

## What is Thumbnail Labs?

Thumbnail Labs is a free, browser-based YouTube thumbnail tester and preview tool. It lets YouTube creators preview how their video thumbnails will appear across real YouTube feed layouts — including Home, Search, Sidebar, Channel Page, and Mobile — before uploading to YouTube.

## What makes Thumbnail Labs different?

Thumbnail Labs is the only free tool that combines three capabilities in one:

1. **Live Feed Simulation**: Your thumbnail is placed inside realistic YouTube feeds populated with real competitor videos from your niche, not generic placeholders.
2. **Side-by-Side A/B Comparison**: Compare your thumbnail against any competitor's video URL, with independent CTR scoring for each side.
3. **AI-Powered CTR Scoring**: Computer vision analyzes your thumbnail for contrast, color saturation, and face detection — the visual signals most correlated with high click-through rates.

## Key Features

- Preview thumbnails across 10+ YouTube layouts (Desktop Home, Search, Sidebar, Channel, Watch History, Watch Later, Mobile Feed, Mobile Compact)
- Live niche search engine with real competitor data
- A/B thumbnail comparison with independent CTR analysis
- AI CTR scoring using contrast, saturation, and face detection
- Title hook analyzer with power word detection and truncation preview
- Brightness, contrast, and saturation adjustment sliders
- Squint/blur test, grayscale, and colorblindness (Protanopia) simulation
- Draft snapshot gallery (save up to 5 variations)
- Pro audit report export as PNG
- Cmd+K command palette for keyboard-first workflow
- Dark mode and light mode
- No signup required, 100% free

## Who is it for?

YouTube creators, thumbnail designers, video production agencies, and anyone who wants to optimize their YouTube video thumbnails for maximum click-through rate before publishing.

## URL

[https://thumbnaillabs.com](https://thumbnaillabs.com)

## Pricing

Free. No signup required.