Jan

Jan is an open-source desktop app for Mac, Windows, and Linux that runs large language models locally so all conversations stay on your own machine. It's aimed at developers, privacy-conscious knowledge workers, and small teams who want a ChatGPT-style assistant without sending data to the cloud, while still allowing optional connections to hosted models like GPT, Claude, and Gemini via API keys. Its main differentiator is offline-first, on-device execution combined with the flexibility to switch between local open models and cloud providers in one interface.