Pull the plug

Goal

Show yourself that chatting needs no internet once setup and the model download are done.

Before you start

This only works after chapters 03 or 04 and 05. Jan's first-time setup and model downloads need the internet. If you install Jan and go straight into a forest, you get a very nice empty app.

Switch the internet off

• Windows: click the network icon at the bottom right of the taskbar → turn on Airplane mode. Using a cable? Unplug it too.
• Mac: Control Centre (top right) → turn Wi-Fi off. Unplug any Ethernet cable.

Open a browser and load any website. It should fail. Good.

Keep chatting

1. In Jan, start a New Chat with Qwen3.5-2B.
2. Ask: Explain compound interest with an example in rupees.
3. It answers. There is nothing to connect to, because the AI is on your laptop.

Close and reopen, still offline

1. Close Jan completely.
   • Windows: close the window, then right-click Jan in the system tray (^ near the clock) → Quit, if it is there.
   • Mac: Cmd + Q.
2. Open Jan again.
3. Your old chats are still in the sidebar. Send a new message. It works.

Turn the internet back on

Turn Airplane mode off (Windows) or Wi-Fi on (Mac). When Jan has internet again, it may check for updates (chapter 08). Your chats are not uploaded anywhere. Jan has no chat sync.

What this proves, and what it does not

• Proves: the AI's thinking happens on your laptop (local inference), and chatting works offline.
• Does not prove: that Jan never uses the internet at other times. Chapter 08 covers that.

Check it works

You got an answer with no internet, and your chat history survived a full restart.

Exercise

Still offline, open the Hub and search for a model. What happens? Write down which parts of Jan need the internet and which do not.