YouTube Bilingual Subtitle Translator

More than a simple translation tool, YouTube Subtitle Translator & Bilingual Helper functions as a comprehensive bilingual assistant that supports language acquisition and accessibility needs across 10 interface languages. Its advanced settings and comprehensive API support enable users to choose from a wide array of AI translation engines and models, with intelligent features like API endpoint testing and smart debouncing for flicker-free viewing. User preferences are preserved via browser sync across devices, and the extension's thoughtful design allows for smooth interactions and real-time subtitle updates as the video plays, making YouTube content accessible and enjoyable regardless of language fluency.

Key Features
Real-time Subtitle Translation: Instant translation on YouTube utilizing various AI providers including OpenAI, Azure OpenAI, Anthropic Claude, Google Gemini, DeepSeek, or custom OpenAI-compatible endpoints

Bilingual Subtitle Display: Presents both original and translated text simultaneously, ideal for language learners, travelers, and multilingual audiences

Smart Debouncing Technology: Eliminates flickering on word-by-word subtitles with intelligent three-tier strategy (immediate translation on sentence-ending punctuation, 500ms delay for partial sentences, 2000ms maximum wait), optimized for news broadcasts and live content

Multilingual Interface: Available in 10 languages (English, Simplified Chinese, Traditional Chinese, Japanese, Korean, Dutch, French, German, Spanish, Ukrainian) with automatic language detection based on browser settings

Extensive Subtitle Customization: Options for text color, font size, and background color to enhance readability and match personal preferences

Draggable Subtitle Overlay: Flexible positioning anywhere on the screen, preventing interference with video content and UI elements

Quick AI Provider Selection: Easy dropdown menu to switch between OpenAI, Azure OpenAI, Anthropic Claude, Google Gemini, DeepSeek, or custom services with smart model auto-fill

API Endpoint Testing: Test your configuration before saving to verify API key, endpoint, and model settings are working correctly with instant feedback

Provider Versatility: Customizable API keys, endpoints, and model names supporting multiple major AI translation services with intelligent provider detection

Persistent Settings: User preferences synchronized across devices via browser sync, ensuring a consistent personalized experience

Intelligent Real-time Monitoring: Monitors subtitle containers and video page events for smooth subtitle updates and automatic reset when navigating videos

User-friendly Popup Interface: Easy setup with API testing, quick toggling, and on-the-fly changes to preferences

How It Works
Install & Setup: Install the extension from your browser's extension store and pin it for convenient access

Configure Your Preferences: Open any YouTube video with native subtitles, click the extension icon to access the popup interface, and select your preferred AI provider from the dropdown menu (OpenAI, Azure, Anthropic, Gemini, DeepSeek, or custom)

Enter Credentials: Input your AI provider API key (stored securely in your browser only), and the extension will auto-fill the appropriate model name based on your provider selection

Test Configuration: Use the built-in API testing feature to verify your setup works correctly before saving, with instant feedback on connection status

Customize Appearance: Choose your target translation language from 20+ supported languages and customize subtitle appearance by setting preferred text color, font size, and background color

Save & Watch: Save your settings to ensure they persist across browsing sessions and devices, then play your chosen video

Automatic Translation: The extension detects and captures on-screen subtitles automatically, with translations appearing instantly in a customizable overlay that you can reposition by dragging anywhere on screen

Smooth Experience: Subtitles update dynamically in sync with video playback without flickering, thanks to smart debouncing technology. When navigating to a new video or enabling/disabling subtitles, the overlay automatically clears and resets to maintain smooth operation without manual interference

Privacy & Security
No personal data collected. Your API key and preferences are securely stored only in your browser. Subtitle texts are processed solely for translation purposes; no browsing history or personal information is accessed or transmitted. All data stays local to your device, with API calls made directly to your chosen AI provider. Please refer to the privacy policy for detailed information.