whisper.cpp

whisper.cpp is a high-performance C++ port of OpenAI's Whisper speech recognition model. It runs locally on CPU and GPU without cloud dependencies, making it ideal for privacy-sensitive and offline use cases.

It supports all Whisper model sizes (tiny to large-v3), real-time transcription, multiple languages, and quantized models for faster inference. Bindings exist for Python, Node.js, Go, and other languages. It can process audio significantly faster than real-time on modern hardware.

whisper.cpp is completely free and open source. Best for developers who need fast, private, offline speech-to-text without API costs.