himomohi/airtranslate

AirTranslate is a macOS application that captures audio playing on your Mac and shows it as live captions with real-time translation in a floating window that stays on top of whatever you are watching. The problem it solves is that many meetings, lectures, videos, and streams do not have subtitles, and routing audio through a microphone to get transcription is slow and lossy compared to capturing the digital audio directly. The app intercepts your Mac's system audio output, transcribes it in real time, and translates it into your chosen language simultaneously. By default it uses Apple's built-in speech recognition and translation frameworks, so no internet connection or account is required for basic use. An optional mode lets you provide your own OpenAI API key to use a more capable AI transcription and translation model for difficult audio or uncommon language pairs. Your API key is stored securely in the macOS Keychain and never leaves your device through the app. You would use this when watching a foreign-language video, attending an online meeting in a language you are still learning, or following a livestream with no captions. A floating caption window keeps translations visible while you focus on other apps. The app saves transcripts as plain text files you can edit or delete. It is a free, open-source download for macOS built with Swift.