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A simple, fast CLI tool to turn any folder of photos and videos into a beautiful, responsive web gallery.

• One command: gallery up
• Caches thumbnails, watches for changes, and serves instantly
• Works great for large folders; runs in the background so your terminal is free

1. Install globally

npm install -g folder-gallery

Note: If Sharp (image processing library) fails to install, the gallery will still work but without thumbnail generation. To enable thumbnails:

# Install Sharp separately if the main install failed
npm install -g sharp

2. Start a gallery in any folder

cd /path/to/photos
gallery up

3. Open in your browser (auto-opens by default)

• Default URL: http://localhost:3000

4. What you’ll see

Tip: Use gallery up -d /path/to/photos --port 3000 to start on a specific path/port.

# Start in the current directory
gallery up

# Start in a specific directory
gallery up -d /path/to/images

# Use a custom port
gallery up --port 8080

# Don’t auto-open the browser
gallery up --no-open

# Stop all gallery servers
gallery down

# Force a rescan of the current gallery
gallery rescan

# Upgrade to latest UI after npm update (keeps thumbnails/metadata)
gallery upgrade

• ✅ Recursively scans images and videos
• ✅ Generates cached thumbnails (prioritized for visible items)
• ✅ Watches for file changes in real-time
• ✅ Runs detached so your terminal is free

• Install notes, platform requirements, and optional tools like FFmpeg: docs/installation.md
• Flags like --max-workers, --ffmpeg-timeout, --disable-video-thumbs: docs/video-thumbnails.md
• Full CLI reference and examples: docs/cli.md
• How the server, cache, and UI work: docs/server.md
• Common issues and fixes: docs/troubleshooting.md

✨ Modern Web Interface

• Organized gallery with folder sections
• Viewport-aware thumbnail generation (prioritizes visible images)
• Pause/resume thumbnail generation at any time
• Real-time thumbnail generation with progress bar
• Instant tiny preview thumbnails for immediate feedback
• Pan and zoom functionality for images
• Video playback support
• Favorite/heart images with persistent storage
• Filter to show only favorited images
• Search images with autocomplete suggestions (Ctrl/Cmd+K)
  • Instant suggestions for filenames and folders as you type
  • Recent search history with keyboard navigation
• Fullscreen mode and dark/light theme toggle
• Responsive design for all devices

🚀 Easy to Use

• Global CLI installation
• Automatic port detection
• Browser auto-launch
• Recursive directory scanning

📱 Media Support

• Images: JPG, PNG, GIF, BMP, WebP, TIFF, SVG
• Videos: MP4, MOV, AVI, MKV, WebM, OGG, M4V, 3GP, WMV, FLV

• Node.js: 18.0.0 or higher
• npm: 6.0.0 or higher (usually bundled with Node.js)
• Operating System:
  • macOS 10.13+ (High Sierra)
  • Linux (Ubuntu 18.04+, CentOS 7+, or equivalent)
  • Windows 10+ (with PowerShell 3.0+)
• Memory: 512MB RAM minimum, 1GB+ recommended for large galleries
• Storage: 50MB for application + additional space for thumbnail cache

• Build tools: build-essential (Ubuntu/Debian) or gcc-c++ (CentOS/RHEL)
• Python: 3.x (for Sharp native compilation)
• Additional packages: May need libvips-dev for Sharp optimization
• FFmpeg (Optional): For real video thumbnails from frame extraction
  • Install: sudo apt-get install ffmpeg (Ubuntu/Debian) or sudo yum install ffmpeg (CentOS/RHEL)

• Xcode Command Line Tools: Required for Sharp compilation
• Install with: xcode-select --install
• tag CLI tool (Optional): For Finder tags support in gallery UI
  • Install: brew install tag
  • Enables reading and writing Finder tags from the gallery
  • Gallery works without it, but tag features will be disabled
• FFmpeg (Optional): For real video thumbnails from frame extraction
  • Install: brew install ffmpeg

• Visual Studio Build Tools or Visual Studio 2019+
• Python: 3.x (for Sharp native compilation)
• PowerShell: 3.0+ (Windows 10+ includes 5.1+)
• FFmpeg (Optional): For real video thumbnails from frame extraction
  • Download from: https://ffmpeg.org/download.html
  • Or install via: choco install ffmpeg (if using Chocolatey)

• Images: JPEG, PNG, GIF, BMP, WebP, TIFF, SVG
• Videos: MP4, MOV, AVI, MKV, WebM, OGG, M4V, 3GP, WMV, FLV

• Viewport-Aware Generation:
  • Only generates thumbnails for visible images first
  • Automatically prioritizes as you scroll
  • Reduces initial wait time for large galleries
  • Background generation continues for off-screen images
• Two-Phase Thumbnail Generation:
  • Phase 1: Instant 64×64 tiny previews (blurred) for viewport items
  • Phase 2: Full 300×300px thumbnails
• Adaptive Batch Processing:
  • Processes 5 items at a time with viewport priority
  • Viewport items: Tiny preview → Full thumbnail
  • Background items: Full thumbnail only
• User Control:
  • Pause/resume thumbnail generation at any time
  • Gallery remains fully usable while paused
  • Resume exactly where you left off
• Thumbnail Size: 300×300px JPEG (quality 80%) + 64×64px tiny preview
• Cache Size: ~10-50KB per full thumbnail + ~2KB per tiny preview
• Memory Usage: ~100-200MB base + ~1-2MB per 1000 images
• CPU Usage: Moderate during initial thumbnail generation, minimal during serving
• Progressive Loading: Server-Sent Events (SSE) for real-time thumbnail updates

• With FFmpeg installed: Real frame extraction from videos
  • Extracts a representative frame at roughly 1/3 of the video duration
  • Creates accurate video thumbnails showing actual content
  • Maintains aspect ratio with padding when necessary
• Without FFmpeg: Graceful fallback to placeholder thumbnails
  • Video thumbnails display a generic play button icon
  • Gallery remains fully functional
  • Video playback still works normally
  • No error messages or logging; seamless experience

• Local Network: Gallery accessible on local network by default
• Port Range: 3000-3099 (automatic port selection if 3000 in use)
• Bandwidth: Minimal - thumbnails cached locally, full images served on-demand

After installation, the postinstall script displays:

• 🎉 Styled installation banner confirming successful setup
• ✅ Dependency status for Sharp (image processing) and macOS tag CLI
• 🚀 Quick start instructions to get your first gallery running
• ⚠️ Installation guidance if optional dependencies are missing

Example postinstall output:

╬════════════════════════════════════════════════════════════╩
║  📸 Folder Gallery - Installed Successfully               ║
╙════════════════════════════════════════════════════════════╜

👤 Created by Brian Lashbrook
📖 View Docs: https://github.com/blashbrook/folder-gallery#readme

✅ Sharp: Image thumbnails enabled
✅ macOS tag: Finder tags enabled  (macOS only)

🚀 Quick Start:
   cd /path/to/photos
   gallery up

• The published npm package only includes runtime files (CLI, server, core JS). Docs, tests, and non-essential assets are excluded.
• Dev extras are gated behind a postinstall that only runs when explicitly requested.

Dev-only postinstall:

# Force dev setup tasks locally (no-op placeholder)
npm run local-install
# Or set env before install
FG_DEV=1 npm install

If you want to install from source or contribute to development:

# Clone the repository
git clone https://github.com/blashbrook/folder-gallery.git
cd folder-gallery

# Install dependencies
npm install

# Link globally for development
npm link

# Link local version for testing
npm run link

# Make your changes...

# Unlink when done
npm run unlink

npm uninstall -g folder-gallery

# Start server in current directory
gallery up

# Start server for specific directory
gallery up -d /path/to/images

# Use custom port
gallery up --port 8080

# Don't open browser automatically
gallery up --no-open

# Scan current directory and show results
gallery scan

# Scan specific directory
gallery scan -d /path/to/images

# Stop all running gallery servers
gallery down

# Force rescan of current directory gallery
gallery rescan

# Remove thumbnails for deleted media files
gallery cleanup

# Delete all .gallery-cache directories (with confirmation)
gallery delete

# Delete cache files in specific directory
gallery delete -d /path/to/clean

# Force delete without confirmation
gallery delete -f

For development or if you prefer not to use the CLI:

# Clone and install dependencies
git clone https://github.com/blashbrook/folder-gallery.git
cd folder-gallery
npm install

# Run standalone server
npm start

# Or specify directory
node server.js /path/to/images

# Development mode with auto-restart
npm run dev

Important: All gallery HTML, CSS, and client-side JS are generated at runtime by JavaScript. There are no static HTML files shipped with the package. The key generators are:

• bin/server-runner.js → generateIndexHTML(): writes .gallery-cache/index.html with embedded CSS/JS and all UI
• bin/server-runner.js → thumbnail pipeline: generates .gallery-cache/thumbnails/*.jpg using Sharp (and FFmpeg optionally)
• bin/gallery.js → CLI: spawns server-runner in the background, manages PID and server-info.json

1. Scanning: Recursively scans directories for images and videos
2. Thumbnails: Automatically generates optimized thumbnails
3. Caching: Stores thumbnails in .gallery-cache directories
4. Serving: Provides a responsive web interface with advanced features
5. File Watching: Automatically detects new/deleted files
6. Smart Caching: Caches scan results for fast loading

• 📋 File Listings: Cached for 30 seconds for instant loading
• 🖼️ Thumbnails: Generated once and cached permanently
• 👀 File Watching: Auto-detects new/deleted files and invalidates cache
• 🔄 Manual Refresh: Use gallery rescan or click "Rescan" button

• Background Processing: Server runs detached, no terminal blocking
• Lazy Thumbnails: Only generated when requested
• Smart Invalidation: Cache updates only when files change
• Efficient Scanning: Skips hidden directories and irrelevant files

• Server Restart: ❌ Not needed - file watching handles new files automatically
• New Files: ✅ Detected automatically via file watching
• Cache Location: .gallery-cache/ in each scanned directory
• Cache Cleanup: Use gallery delete to remove cache files

GET /api/gallery

Returns JSON with all images organized by directory structure.

GET /progress

Real-time thumbnail generation progress and updates:

• request_viewport_items: Server requests visible items from client
• tiny_preview_ready: When 64×64 preview is generated
• thumbnail_ready: When full 300×300 thumbnail is complete
• global_thumbnail_progress: Overall progress with current file
• thumbnail_paused: When generation is paused/resumed

POST /api/rescan

Invalidates cache and rescans directory for new files.

POST /api/viewport-items

Client reports which images are currently visible in viewport. Payload: { relativePaths: string[] }

POST /api/pause-thumbnails

Toggles pause state for thumbnail generation. Returns: { isPaused: boolean }

GET /image/:path

Serves the full-resolution image file.

GET /static/*

Serves thumbnails and cached files from .gallery-cache/.

At runtime (per scanned directory):

/path/to/photos/
├── .gallery-cache/
│   ├── index.html          # Generated by bin/server-runner.js (generateIndexHTML)
│   ├── thumbnails/         # Generated thumbnails (*.jpg)
│   ├── gallery.pid         # Server PID for process management
│   └── server-info.json    # Port and runtime info for CLI open/attach
└── <your media files>

Source layout (repo):

folder-gallery/
├── bin/
│   ├── gallery.js         # CLI: up/down/scan/delete, spawns server-runner
│   └── server-runner.js   # Background server; generates .gallery-cache and UI
├── server.js              # Legacy standalone server (dev/back-compat)
├── metadata.js            # Metadata utilities
├── macos-tags.js          # macOS Finder tags integration
├── package.json
└── docs/

• PORT: Server port (default: 3000)
• TAG_PATH: Path to the tag CLI tool (default: /opt/homebrew/bin/tag)
  • Only used on macOS for Finder tags functionality
  • Set this if tag is installed in a non-standard location

• First argument: Directory to scan (default: current directory)

• --max-workers <n>: Limit concurrent FFmpeg extractions (default: 2)
• --ffmpeg-timeout <ms>: Per-file FFmpeg timeout in milliseconds (default: 20000)
• --disable-video-thumbs: Disable real video frames (always use placeholder)

# Scan current directory on port 3000
npm start

# Scan specific directory
node server.js ~/Pictures

# Use different port
PORT=8080 node server.js /path/to/images

• Viewport-aware generation:
  • Prioritizes thumbnails for images currently visible on screen
  • Automatically detects and prioritizes as you scroll (500px buffer)
  • Background generation continues for off-screen images
• Two-phase generation for optimal UX:
  1. Instant tiny previews (64×64) appear immediately for viewport items
  2. Full-quality thumbnails (300×300) load progressively
• Pause/Resume control:
  • Pause button replaces rescan button during generation
  • Click to pause/resume at any time
  • Gallery remains fully usable while paused
  • Icon changes: ⏸️ (pause) ↔️ ▶️ (resume)
• Real-time progress: Slim progress bar in header with current file name
• Individual loaders: Spinner on each thumbnail during generation
• Uses Sharp for high-quality, fast image processing
• Thumbnails are cached and only regenerated if missing
• JPEG format with 80% quality for optimal file size

• Heart/favorite images: Click heart icon on any image
• Persistent storage: Favorites saved in browser localStorage
• Filter view: Toggle to show only favorited images
• Multiple interfaces:
  • Gallery view: Heart button appears on hover (top-right)
  • Modal view: Heart button in zoom controls
  • Header: Filter button to show only favorites
• Visual feedback: Red filled heart when favorited, outline when not

• Path traversal protection prevents access to files outside scan directory
• Only serves files with supported image extensions
• Base64-encoded filenames prevent filename conflicts

• Lazy loading for thumbnails
• Efficient caching of generated thumbnails
• Asynchronous directory scanning
• Minimal memory footprint

• Responsive column layout (2-5 columns based on screen size)
• Touch-friendly image previews
• Optimized for various screen sizes
• Progressive loading with tiny previews for faster initial display
• Efficient loading on mobile networks

• Header Buttons:
  • Fullscreen: Toggle fullscreen mode
  • Search: Filter images by filename or folder name (Ctrl/Cmd+K)
  • Theme: Switch between dark and light themes
  • Pause/Resume: Pause or resume thumbnail generation (only visible during generation)
  • Rescan: Force directory rescan (hidden during generation)
  • Favorites Filter: Show only hearted images (highlights red when active)
• Keyboard Shortcuts:
  • Ctrl+K or Cmd+K: Open/close search
  • Escape: Close search or modal
  • Arrow Left/Right: Navigate images in modal view
• Modal Controls (Image Viewer):
  • Heart: Favorite/unfavorite current image
  • Zoom In/Out: Control image zoom level
  • Reset: Return to 100% zoom
  • Close: Exit modal (or press ESC)
• Gallery View:
  • Heart icon on hover: Favorite images directly from gallery
  • Click image: Open in full-screen modal
  • Organized by folder sections with titles
  • Automatic viewport detection for optimized loading

Q: Installation fails with "Node.js version too old" error

• Update Node.js to 18.0.0 or higher from nodejs.org
• Verify version: node --version

Q: Sharp installation fails on Linux

• Install build tools: sudo apt-get install build-essential python3-dev (Ubuntu/Debian)
• Or: sudo yum install gcc-c++ python3-devel (CentOS/RHEL)
• For better performance: sudo apt-get install libvips-dev

Q: "gyp ERR!" during installation on Windows

• Install Visual Studio Build Tools or Visual Studio with C++ tools
• Alternative: Install windows-build-tools: npm install -g windows-build-tools
• Ensure Python 3.x is installed and in PATH (for Sharp native compilation)

Q: Sharp installation fails on macOS

• Install Xcode Command Line Tools: xcode-select --install
• Update macOS to latest version if using older hardware
• For Apple Silicon Macs: Ensure Node.js is ARM64 version

Q: "Permission denied" errors during installation

• On macOS/Linux: Use sudo or configure npm for global installs without sudo
• Configure npm: npm config set prefix ~/.local and add ~/.local/bin to PATH
• On Windows: Run PowerShell as Administrator

Q: Gallery server won't start

• Check Node.js version: node --version (must be 18+)
• Verify port availability: netstat -an | grep 3000
• Check file permissions in installation directory

Q: Images aren't showing up

• Ensure image files have supported extensions
• Check file permissions
• Verify the directory path is correct

Q: Thumbnails not generating

• Sharp may need additional dependencies on some systems
• Check console for thumbnail generation errors
• Ensure write permissions to static/thumbnails/ directory

Q: Server won't start

• Check if port 3000 is already in use
• Try a different port: PORT=8080 npm start
• Ensure Node.js version 18+ is installed

• Unable to scan directory: Check directory permissions and path
• Failed to generate thumbnail: Image file may be corrupted or unsupported format
• Access denied: File is outside the scan directory (security protection)

• Node.js 18.0.0 or higher
• npm or yarn package manager

• express: Web server framework
• sharp: High-performance image processing
• multer: File upload handling (for future features)

1. Fork the repository
2. Create a feature branch
3. Make your changes
4. Test thoroughly
5. Submit a pull request

MIT License - feel free to use this project for personal or commercial purposes.

• Initial release
• Basic gallery functionality
• Thumbnail generation
• Responsive design
• Directory organization
• Metadata support framework