I built a Mac app that automatically generates and translates subtitles for videos (fully local)
Hey everyone!
I recently developed a Mac app that runs locally to automatically generate and translate video subtitles. I wanted to share the story and the reasoning behind it.
Why did I build this?
I love watching foreign-language videos, especially gaming content like StarCraft commentary. But I constantly ran into the same problem: no subtitles, which really hurt the viewing experience.
I wanted something that could automatically generate subtitles—and even translate them—to help me actually understand the content.
Making subtitles manually is tedious and time-consuming, so the idea of automatic generation plus quick export/burn-in was born.
That's the main reason I built this. The goal is simple but practical: solve the everyday pain points of understanding foreign-language videos (for myself and my team).
How it works
The pipeline isn't too complicated—just a few steps:
VAD slicing → ASR transcription → punctuation only (no word changes) → forced alignment to words → professional sentence segmentation → sentence-by-sentence translation
Tech stack:
- Silero-VAD (voice activity detection)
- Qwen3-ASR (speech recognition)
- Qwen3-ForcedAligner (alignment)
Try it out
It's currently available on TestFlight—would love for you to give it a try and share your feedback:
👉 https://testflight.apple.com/join/m7KGHndP
Any thoughts, suggestions, or bug reports are super welcome. Thanks for reading!