Free Offline Transcription App for Mac: How I Built Local Whisper with whisper.cpp + CoreML
I built a fully offline, free transcription app for Mac called **Local Whisper** that captures both microphone input and system audio (including your meeting partner's voice). It runs whisper.cpp with CoreML acceleration on Apple Silicon, achieving near-real-time transcription without sending any data to the cloud. This post covers the architecture, the real-time optimization tricks, and the system audio capture method that took the most effort to crack.