Create professional YouTube Thumbnails with flexible grid layouts supporting 1-6 images! 🎨
This powerful app is perfect for YouTube vlogs, tutorials, cooking videos, travel content, "Day in the Life" (DITL) videos, and more! With an intelligent Smart Layout system, 8 different grid configurations, and NEW flexible image requirements, you can generate professional-looking thumbnails that help boost engagement on your channel.
🆕 Latest Updates (v3.0.0):
- ✨ Universal image support: Create thumbnails with ANY layout mode regardless of image count - smart adaptation included!
- 🖼️ Text Behind Image: Add meaningful texts that automatically fits ANY thumbnail with beautiful fonts, colors, etc.
- ⚡ ENTER key shortcut: Instant thumbnail creation from anywhere in the app
- 🧠 Enhanced AI analysis: Improved image analysis for better automatic layout selection
- 🔧 Mac App Store ready: Pre-built packages available for App Store submission
- ⚙️ Requirements
- 📦 Installation
- 🪄 Features
- 🎨 Grid Layout System
- 🚀 Performance & Optimization
- 🧪 Testing
- 🛠️ Development
- 👨🍳 Who made this?
- 🎥 Watch me build apps like this
- ⚖️ License
- Node.js v18+ (latest LTS version recommended) 🚀
- Electron v22+ for cross-platform desktop support
- macOS 10.14+ for Mac App Store builds
# Clone the repository
git clone https://github.com/pH-7/youtube-thumbnail-creator.git
cd youtube-thumbnail-creator
# Install dependencies (includes Sharp.js image processing)
npm install
# Launch the application
npm start- Node.js: v18+ (LTS recommended)
- Operating System: macOS 10.14+, Windows 10+, or Ubuntu 18.04+
- Memory: 4GB RAM minimum (8GB recommended for large image processing)
- Storage: 500MB free space for application and dependencies
- 1-6 images support: Create thumbnails with any number of images
- Smart adaptation: System automatically adjusts layouts when you have fewer images than the selected grid requires
- No workflow interruptions: "Create Thumbnail" button always available when you have at least 1 image
- Standard YouTube dimensions: All thumbnails output at 1280×720 pixels
- Linear layouts: 1×2, 1×3, 2×1, 3×1 for side-by-side and stacked arrangements
- Grid layouts: 2×2, 2×3, 3×2 for complex compositions with multiple subjects
- Single layout: 1×1 for spotlight focus on one powerful image
- Smart Auto mode: Automatically selects optimal layout based on image analysis
- Advanced image analysis: Considers aspect ratios, visual complexity, and subject detection
- Entropy calculation: Assesses visual complexity for optimal grid placement
- Color variance analysis: Evaluates saturation and vibrancy for balanced compositions
- Edge detection: Identifies prominent subjects for strategic positioning
- Confidence scoring: 0-1 ratings for layout recommendations
- Universal ENTER shortcut: Create thumbnails instantly from anywhere in the app
- Drag & drop support: Rearrange images by dragging between slots
- Real-time preview: See exactly how your thumbnail will look before exporting
- Smart status messages: Clear feedback on image counts and layout adjustments
- Delimiter controls: Adjust width, color, and tilt angle for separators between images
- Image enhancement: Choose from None, Light, Medium, or High enhancement levels
- YouTube optimization: Automatic metadata stripping and compression optimization
- Custom naming: Optional output filename customization
- Automatic organization: Saves to dedicated folder in Pictures directory
- Performance optimization: Special handling for large grid layouts (6+ images)
- File management: Open output folder directly from the app
- Batch processing: Efficient handling of multiple images with error resilience
The app supports 8 optimized grid configurations:
| Layout | Configuration | Max Images | Best Use Cases |
|---|---|---|---|
| 1×1 | Single image | 1 | Hero shots, portraits, single subject focus |
| 1×2 | Side by side | 2 | Before/after comparisons, dual perspectives |
| 2×1 | Vertical stack | 2 | Top/bottom scenes, timeline progression |
| 1×3 | Horizontal strip | 3 | Step-by-step tutorials, sequence shots |
| 3×1 | Vertical tower | 3 | Vertical storytelling, progression shots |
| 2×2 | Four square | 4 | Multiple subjects, variety content |
| 2×3 | Six grid | 6 | Complex stories, multiple scenes |
| 3×2 | Six grid alt | 6 | Alternative 6-image arrangement |
The Auto mode uses advanced analysis to recommend optimal layouts:
// Analysis factors include:
- Aspect ratio distribution (portrait/landscape/square detection)
- Visual complexity via entropy calculation
- Color variance and saturation levels
- Prominent subject detection using edge analysis
- Visual weight calculation for balanced compositions
- Confidence scoring (0-1) for layout recommendations- Adaptive UI: Image slots show/hide automatically based on selected layout
- Smart validation: Real-time feedback with helpful user guidance
- Flexible workflow: Create thumbnails with any image count - no restrictions
- Universal shortcuts: ENTER key works anywhere in the app for instant creation
- Progressive processing: Optimized performance for 2×3 and 3×2 layouts (6+ images)
- Quality scaling: Adaptive compression maintains quality while managing file sizes
- Memory management: Efficient buffer handling prevents memory issues with multiple images
- Batch processing: Parallel image analysis with comprehensive error resilience
- Metadata stripping: Removes EXIF data for faster uploads and privacy
- Progressive encoding: PNG optimization for better compression ratios
- Adaptive filtering: Smart compression algorithms preserve visual quality
- Color space optimization: Ensures consistent colors across different devices
- File size reduction: 25-35% smaller files without visible quality loss
- Path compatibility: Windows long path validation and cross-platform support
- Directory management: Automatic folder creation with proper error messages
- Image format validation: Supports JPG, PNG, WebP with intelligent fallbacks
- Layout validation: Prevents invalid configurations and provides helpful guidance
- User-friendly messages: Clear, actionable error descriptions
Run the test suite to verify all functionality:
npm test- Grid Layout System: Validates all 8 layout configurations
- Image Analysis: Tests aspect ratio and orientation detection
- Smart Algorithm: Verifies layout selection logic
- Thumbnail Dimensions: Ensures YouTube compliance
- Cell Calculations: Validates grid positioning math
✅ 12 tests passing - Complete test coverage across all core functionality:
✓ Grid Layout System (4 tests)
✓ Image Analysis (2 tests)
✓ Smart Layout Algorithm (4 tests)
✓ Thumbnail Configuration (2 tests)
✓ Application loads without errors
Test Suites: 1 passed, 0 failed
Tests: 12 passed, 0 failed
Time: ~0.2s, estimated ~0.1s per test
# Clone and setup
git clone https://github.com/pH-7/youtube-thumbnail-creator.git
cd youtube-thumbnail-creator
npm install
# Start development
npm start
# Run tests
npm test
# Build for production
npm run distnpm start- Launch the Electron app in development modenpm test- Run the comprehensive Jest test suitenpm run pack- Package the app without distributionnpm run dist- Build distributable packages for all platformsnpm run mas-dev- Build Mac App Store development versionnpm run rebuild-sharp- Rebuild native Sharp.js dependencies
- Frontend: HTML5, CSS3, Vanilla JavaScript with modern ES6+ features
- Backend: Electron main process with Node.js APIs
- Image Processing: Sharp.js for high-performance image manipulation
- Testing: Jest for unit and integration testing
- Build System: Electron Builder for cross-platform packaging
Pierre-Henry Soria. A super passionate and enthusiastic software engineer! 🚀 True cheese 🧀 , coffee, and chocolate lover! 😋 Reach me at pH7.me 💫
☕️ Enjoying this project? Buy me a coffee (my favorite is almond flat white ☕️)
Subscribe to my YouTube channel to watch me explain how I build apps from scratch, just like this one: @pH7Programming 🎬
This YouTube Thumbnail Creator is licensed under the MIT License.
