3-Panel Composer is a full‑featured WYSIWYG editor with built‑in REST API, SQLite storage, image upload, dark mode, tables, and more — all in one PHP file.

• ✅ 3‑panel UI (documents | editor | stats)
• ✅ Toolbar: bold, lists, align, links, images, tables, undo/redo, source view
• ✅ Drag & drop image upload
• ✅ Auto‑save drafts, dark mode, fullscreen
• ✅ REST API (save, load, list, delete, upload)
• ✅ No external libraries

🎮 Live demo →

POST   /api/save     { "title": "My Doc", "content": "<p>Hello</p>" }
GET    /api/load?id=1
GET    /api/list
DELETE /api/delete   { "id": 1 }
POST   /api/upload   (multipart form-data: field "image")

All responses are JSON. CORS enabled by default (set API_ENABLE_CORS=false to disable).

Edit the top of the downloaded file to change:

// Database file
define('DB_FILE', '3pc.sqlite');
// Upload directory
define('UPLOAD_DIR', 'uploads');
// Max file size (bytes)
define('MAX_FILE_SIZE', 5 * 1024 * 1024);
// Allowed image extensions
define('ALLOWED_IMG_EXT', ['jpg', 'jpeg', 'png', 'gif', 'webp']);
// Disable CORS if needed
define('API_ENABLE_CORS', false);
// Debug mode (shows errors)
define('DEBUG_MODE', true);

// TOOLBAR BUTTONS - set any to false to hide that button
$TOOLBAR_BUTTONS = [
    'bold' => true, 'italic' => true, 'underline' => true,
    'ul' => true, 'ol' => true,
    'alignLeft' => true, 'alignCenter' => true, 'alignRight' => true,
    'link' => true, 'image' => true, 'table' => true,
    'undo' => true, 'redo' => true, 'source' => true,
    'darkMode' => true, 'fullscreen' => true
];

To embed the editor in your own script: Copy the whole file or use the API endpoints via AJAX from any frontend. The editor UI is self-contained.