Jan

Jan is a desktop assistant that runs entirely on your machine by default. It is open source, works offline, and stores conversations as plain files on your disk rather than in someone else's account.

What it does

• Runs local models with a built-in engine, downloading open weights from within the app and using GPU acceleration where available
• Connects to cloud models too — bring an API key for a hosted provider when a local model is not strong enough for a particular task
• Exposes a local API so other tools on your machine can use the model Jan has loaded
• Supports extensions for adding capabilities and integrations
• Keeps your data local: threads, settings, and models live in a folder you control

Why choose it

Jan is a good fit when privacy is non-negotiable, when you work somewhere without reliable internet, or when you simply want a chat client that does not depend on a subscription staying active. Because it is open source and file-based, nothing is locked away if you decide to move on. Free to download for macOS, Windows, and Linux.