Hercules

Real-time YouTube video translation powered by ElevenLabs AI dubbing.

What is Hercules?

Hercules is a Chrome extension that translates YouTube videos into 20+ languages in real-time. It uses ElevenLabs' AI dubbing technology to preserve the original speaker's voice characteristics while translating the content.

Supported Languages

English, Spanish, French, German, Italian, Portuguese, Polish, Hindi, Japanese, Korean, Chinese, Arabic, Russian, Turkish, Dutch, Swedish, Indonesian, Filipino, Vietnamese, Thai

How It Works

1. Navigate to any YouTube video
2. Open the Hercules side panel
3. Select your target language
4. Click "Translate Video"
5. Wait for ElevenLabs to process the video (2-5 minutes depending on length)
6. The dubbed audio plays in sync with the video while the original audio is lowered

Architecture

hercules/
├── chrome-extension/     # Extension manifest and background scripts
├── pages/
│   ├── side-panel/       # Language selection UI
│   └── content/          # YouTube video integration
├── packages/             # Shared utilities and storage
└── server/               # Backend API with Redis caching

Backend Server

• Express.js API server
• Redis for job queuing and caching dubbed videos (7-day cache)
• ElevenLabs API integration for AI dubbing

Chrome Extension

• Side Panel - Clean UI for language selection and playback control
• Content Script - Syncs dubbed audio with YouTube video (handles play/pause, seek, speed changes)

Installation

Prerequisites

• Node.js >= 18
• pnpm (npm install -g pnpm)
• Redis server running locally
• ElevenLabs API key

Backend Setup

cd server
cp .env.example .env
# Add your ELEVENLABS_API_KEY to .env

# Start Redis (if not already running)
redis-server

# Start the server
npm run dev

Extension Setup

# Install dependencies
pnpm install

# Development mode (with hot reload)
pnpm dev

# Or production build
pnpm build

Load Extension in Chrome

1. Open chrome://extensions
2. Enable "Developer mode"
3. Click "Load unpacked"
4. Select the dist folder

Configuration

Environment Variables

Create a .env file in the server directory:

ELEVENLABS_API_KEY=your_api_key_here
REDIS_URL=redis://localhost:6379
PORT=3001

Extension Settings

The extension stores settings in Chrome's local storage:

• Target language (default: Spanish)
• Volume level (default: 100%)
• Server URL (default: http://localhost:3001)

API Endpoints

Endpoint	Method	Description
/api/dubbing/languages	GET	Get supported languages
/api/dubbing/create	POST	Create a new dubbing job
/api/dubbing/status/:jobId	GET	Check job status
/api/dubbing/audio/:dubbingId/:lang	GET	Stream dubbed audio
/health	GET	Health check

Tech Stack

• Frontend: React, TypeScript, Tailwind CSS
• Build: Vite, Turborepo
• Backend: Express.js, Redis
• AI: ElevenLabs Dubbing API

Limitations

• ElevenLabs dubbing is not truly real-time - videos need to be processed first
• Processing time: ~2-5 minutes for a 10-minute video
• Maximum video length: 2.5 hours
• Requires ElevenLabs API credits

License

ISC