Why we built Alt even though there are already tons of AI notetakers
Hey everyone,
I’m Coby, a maker from Korea.
I studied CS and Industrial Design at KAIST, Korea’s top engineering school.
As you all know, there are countless AI note-taking apps out there. So why build another one?
The reason is actually pretty simple, and I wanted to share that story.
Everything started with my friend Andrew, who told me he was running his own speech-to-text model locally just to take notes during class.
When I asked why, he said most AI notetakers limit you to around 300 minutes a month — basically just 3–4 lectures before you hit the cap.
He tried looking for unlimited options, including some on-device tools, but the experience just wasn’t usable. Classroom environments are noisy, and Korean speech recognition accuracy was too low to rely on.
So… there just wasn’t a tool that actually solved our problem.
That’s why we decided to build one.
We started by developing a high-performance speech recognition engine that could run efficiently on a MacBook. I spent months fighting memory usage and battery drain. To make the ASR pipeline fast enough, I even spun off an open-source repo — and that’s how we ended up building Lightning-SimulWhisper, which turned out to be about 15× more efficient than the best engines we benchmarked. (It got 300+ stars on Github!)
With that tech, we launched Alt, an on-device AI notetaker for lectures (and it works well for meetings too):
Unlike other tools, the core transcription engine runs locally on your device.
Unlimited Transcription: Since it uses your hardware, there are no hourly limits.
100% Free Tier: The local transcription will always be free.
Privacy First: Your audio doesn't need to leave your laptop.
Battery Efficient: Optimized for macOS and Apple Silicon (ANE support).
Study Harder, Not Longer: Includes AI Chat, PDF summary, Quiz generator, and AI Notes Assistant.
We did not start this project to make money. (We added a Pro plan only because some users specifically wanted GPT 5.1 or Gemini 3 level summaries.)
Our main goal was to help students study without worrying about usage limits, so the core app is completely free and unlimited. Since everything runs locally with no server or API costs, we were able to make that possible.
I hope Alt is useful for you. If you have feedback, please let us know so we can keep improving
If our story resonated with you, an upvote or comment would mean a lot.
Thanks for reading.
Coby and Andrew, Alt
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