rockbenben/subtitle-translator — reverse-engineered prompt

Build me a browser based subtitle translator that feels fast and simple to use. I want to drag in one file or a big batch of subtitle files, including .srt, .ass, .vtt, and .lrc, then translate them into more than 120 languages. It should support common translation services and major AI models like OpenAI, Claude, Gemini, DeepL, Google, and custom compatible endpoints, with my API keys stored only in the browser so nothing goes through your server.

Please keep the subtitle timing and structure intact, only translate the spoken text, and let me export normal translated files or bilingual subtitles with the translation above or below the original. I also want multi language output in one run, optional format conversion between supported subtitle types, and a text only export for summarizing scripts. Add batch progress, success and failure status, caching so refresh does not lose work, and a single file preview mode. If anything is unclear, look up current docs online and make it polished and production ready.