Quick Answer
Jan is fully open source with an extension system. LM Studio has a more polished UI and a larger built-in model library. For power users who want customization, choose Jan. For ease of use, choose LM Studio.
Updated: 2026-05
Key Takeaways
Jan (github.com/janhq/jan) is MIT-licensed and fully open source β you can read, fork, and modify the code. LM Studio (lmstudio.ai) is proprietary software that is free to use but closed source. Jan ships an extension system that lets developers add custom functionality, a feature LM Studio does not offer.
Real extension use cases include: connecting Jan to cloud APIs (OpenAI, Anthropic, Groq) for hybrid local/cloud workflows, adding custom prompt templates and chat presets, and integrating with external tools like Obsidian for note-taking. Around 30 community extensions exist as of May 2026.
LM Studio's main advantage is its built-in model store. You can browse, preview, and download hundreds of GGUF models without leaving the app. Jan requires you to find models on Hugging Face or import them manually β more friction for users who just want to get started quickly.
For developers who want to build on top of the application, Jan's open-source codebase and extension API are meaningful advantages. For everyone else, the choice comes down to which workflow matches your daily use.
Use Jan if you want to extend the app, run it on Linux, or need AMD GPU support. Use LM Studio if you want a polished experience with a built-in model library and do not need customization.
For the full comparison with setup steps and API details, see the Jan vs LM Studio in-depth guide.
| Feature | Jan | LM Studio |
|---|---|---|
| License | MIT (open source) | Proprietary (free) |
| OS support | Mac / Windows / Linux | Mac / Windows |
| GPU backends | NVIDIA + AMD | NVIDIA only |
| Model library | 3rd-party (Hugging Face) | Built-in store |
| Best for | Customization / extensibility | Ease of use / model variety |