Jan AI

Jan AI runs the whole conversation on your hardware, so the app works with no internet connection at all. Your messages and the model's replies go straight to local storage instead of a server. Nothing leaves the machine. That's the core reason people pick it over a hosted chatbot. If you connect a remote API later, that's a choice you make, not a default. Simple as that.

The app ships with a local API server that speaks the same format as OpenAI's endpoints, so it returns responses your existing code already knows how to read. Start it from Settings and it listens on http://127.0.0.1:1337. Any tool or script that already talks to OpenAI can point at that address with a one-line change. For developers, this turns a free download into a drop-in backend for testing and small deployments. Handy.

A built-in hub lets you browse and download popular open models, and you can paste a Hugging Face link to pull something specific if the one you want isn't listed in the default catalog. Jan AI supports the GGUF format and runs on engines including llama.cpp, with TensorRT-LLM as another option for people who want faster inference on supported hardware. Switching models mid-conversation is quick, so you can compare a small fast model against a bigger one for the same task. Want a quick answer? Grab a tiny model. Need depth? Load a larger one.

One app covers Windows, macOS, and Linux, and there's a Docker path for server setups. The Jan.ai desktop interface is the same across systems, so what you learn on a laptop carries over to a desktop without relearning anything. For teams running mixed hardware, that consistency saves the kind of setup fiddling that usually eats an entire afternoon and leaves everyone annoyed.

Jan AI is built as an extensible framework, and its own features sit on top of that layer. Developers can add plugins and build custom assistants with their own instructions. You can also attach files like PDFs or text documents and let the model read them, which is useful when you're summarizing a long report or pulling answers out of a manual instead of pasting text by hand. It's the part that keeps the app from being just a chat box.

Conversations are stored as local files, which means you can delete, export, or migrate them whenever you like. You aren't locked into a vendor whose export button mysteriously doesn't exist, and you don't have to file a support ticket just to get your own chat history back. If you decide to leave, your history travels with you. No export wizard. No waiting.