AST - AI Subtitle Translator

Translate Udemy, YouTube, NVIDIA Academy, and Vimeo subtitles with full-context LLM providers.

AST - AI Subtitle Translator translates Udemy course subtitles into the language of your choice. It also supports NVIDIA Academy, YouTube, and Vimeo. Beyond instant subtitle translation via Google Translate, you can use LLM AI to translate content naturally and in the style you prefer. While the AI translation is being prepared, the original or the quick-translated subtitles are shown. You can use a wide range of models from Google Gemini, OpenAI GPT, Anthropic Claude, NVIDIA NIM, and OpenRouter, and Custom LLM support lets you bring your own AI model. An API key is required for everything except Google Translate. Get a Google AI API key first and try 'Gemini 3.1 Flash Lite' for fast responses and great translations. Google AI's free API key quota resets daily, so it's more than enough for regular use. # Key Features - Subtitle translation for Udemy courses, NVIDIA Academy courses, YouTube videos, and Vimeo videos - Fast translation using Google Translate (default setting) - Choose any subtitle language offered by the video as the translation source - AI contextual translation that accounts for the flow of the original text - Subtitle display, repositioning, and width adjustment - Customizable subtitle font, color, shadow, outline, and background color - Natural, Lecture, Technical, Custom 1 (Star Instructor), and Custom 2 translation styles - Chunked and parallel translation for long video subtitles, with translation caching - Password-based encrypted backup/restore of settings, including API keys - Falls back to the original or quick-translated subtitles if AI translation fails # MIT License # Key Changes [ v0.1.2 (2026-07-19) ] - Added "Simple Settings" mode