Handy is a free, open-source, extensible speech-to-text desktop application that works completely offline on Windows, macOS, and Linux. It leverages local AI models like Whisper and Parakeet V3 for privacy-focused transcription, allowing users to press a shortcut, speak, and paste text directly into any app without sending audio to the cloud. Key features include GPU acceleration, automatic language detection, and high extensibility for developers.