Jan

For all the power of cloud AI like ChatGPT, some people want something different: AI that runs on their own computer — private, offline, and free. That’s exactly what Jan delivers. It’s a free, open-source desktop app that lets you download and run open-source language models locally, turning your laptop into its own AI assistant with no cloud involved.

If privacy, independence, or simply not paying per token matters to you, Jan is one of the most important tools in this category. This guide covers how it works, what it’s good for, and its honest trade-offs.

What is Jan?

Jan is an open-source desktop application for running local AI models. You install it, pick a model from its built-in catalog (or bring your own), download it once, and then chat with it — entirely on your hardware. It’s often described as the “ChatGPT that runs on your computer.”

Because everything runs locally:

• Nothing leaves your device — full privacy.
• It works offline — no internet required after the model is downloaded.
• It’s free — no subscription, no per-token billing.
• It’s open source — the code is transparent and community-developed.

How Jan works

The workflow is simple:

1. Install Jan on Windows, macOS, or Linux.
2. Browse the model catalog — pick an open-source model matched to your hardware (the app shows sizes and requirements).
3. Download the model — one time, stored on your disk.
4. Chat — a familiar assistant interface, but powered entirely by your machine.

Jan also offers local servers and APIs, so developers can build on it, and it supports the OpenAI-compatible API format — meaning tools built for cloud models can often point at Jan instead.

Key features

Local-first privacy

All processing on-device. Your prompts, documents, and conversations stay on your computer.

Offline capability

No internet needed once a model is downloaded — perfect for travel or restricted environments.

Model catalog

Browse and download many open-source models directly in the app, sized to your hardware.

Free and open source

No cost, no account, transparent code you can inspect and extend.

Extensible

Local API servers and integrations for developers who want to build on local AI.

Who is Jan for?

• Privacy-conscious users who won’t send sensitive data to a cloud AI.
• Developers and tinkerers who want hands-on control of open-source models.
• People with strong hardware (gaming PCs, Mac Studios) who want maximum capability locally.
• Anyone who wants AI without a subscription — your computer is the only cost.

Pricing

Jan is free — the app is open source under the Apache 2.0 license, and the models you run are open-source downloads. There’s no subscription and no per-token cost. Your real cost is hardware: a capable computer with enough RAM and ideally a GPU makes a dramatic difference in model quality.

Advantages

• Complete privacy — nothing leaves your device.
• Works offline — no cloud, no outages, no censorship of your local model.
• Free forever — open source, no subscriptions.
• No account required — just install and use.
• Transparent and hackable — inspect the code, extend it, point your own tools at it.

Limitations and honest considerations

• Smaller model ceiling — cloud models like the latest GPT or Claude are far larger than what most home hardware can run; expect a capability gap.
• Hardware matters — weak laptops get weak results; the best experience needs serious RAM/GPU.
• You manage models — downloads, storage, and version upkeep are on you.
• Not a drop-in equal — for most people, cloud assistants remain more capable for daily work.

Alternatives and comparisons

Jan sits alongside other local-AI options like Ollama (a command-line-focused local model runner) and LM Studio. Cloud assistants — ChatGPT, Claude, Gemini — offer stronger models but less privacy. A common setup: cloud AI for everyday tasks, Jan for anything sensitive. It’s not either-or.

The bottom line

Jan proves that you don’t need a cloud subscription to have an AI assistant — a good computer running an open-source model is a genuinely capable, completely private alternative. If privacy, offline use, or independence from subscription pricing matters to you, Jan is the cleanest way to get it. Download a small model first, feel how fast local AI runs, then size up if your hardware allows.

Tip: Start with a small model (a few GB) even on a modest laptop — it runs surprisingly well, and you can always upgrade once you see your machine’s real limits.

Official resource: Jan