--- title: "jan vs LeanCopilot" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/janhq-jan-vs-lean-dojo-leancopilot" tools: ["janhq-jan", "lean-dojo-leancopilot"] --- # jan vs LeanCopilot *GraphCanon updated Jul 11, 2026* ## Verdict Pick jan when jan is primarily TypeScript; LeanCopilot is C++; pick LeanCopilot when leanCopilot is primarily C++; jan is TypeScript. [jan](https://jan.ai/) reports 43k GitHub stars, 2.9k forks, and 387 open issues, last pushed Jul 10, 2026. [LeanCopilot](https://leandojo.org/leancopilot.html) has 1.3k stars, 126 forks, and 4 open issues, last pushed Jun 20, 2026. Figures are from public GitHub metadata via [jan's repository](https://github.com/janhq/jan) and [LeanCopilot's repository](https://github.com/lean-dojo/LeanCopilot). | | [jan](/tools/janhq-jan.md) | [LeanCopilot](/tools/lean-dojo-leancopilot.md) | | --- | --- | --- | | Tagline | open source alternative to ChatGPT that runs offline locally | LLMs as Copilots for Theorem Proving in Lean | | Stars | 43,499 | 1,299 | | Forks | 2,896 | 126 | | Open issues | 387 | 4 | | Language | TypeScript | C++ | | Adopt for | Jan is a TypeScript-based, self-hosted chatbot application that acts as an offline alternative to services like ChatGPT. | - | | Persona | - | - | | Runtime | - | - | | License | Other | MIT | | Categories | Inference & Serving, LLM Frameworks | Inference & Serving, LLM Frameworks | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [jan](/tools/janhq-jan.md) | [LeanCopilot](/tools/lean-dojo-leancopilot.md) | | --- | --- | --- | | Maintenance | Very active (96%) | Active (82%) | | Days since push | 1d | 20d | | Open issues (now) | 387 | 4 | | Full report | [trust report](/tools/janhq-jan/trust.md) | [trust report](/tools/lean-dojo-leancopilot/trust.md) | ## Decision facts: jan - **Adopt for:** Jan is a TypeScript-based, self-hosted chatbot application that acts as an offline alternative to services like ChatGPT. ## Choose when ### Choose jan if… - jan is primarily TypeScript; LeanCopilot is C++. - License: jan is Other, LeanCopilot is MIT. - Tags unique to jan: chatgpt, gpt, llamacpp, localai. - - If you require an offline-capable AI assistant for environments without internet access. ### Choose LeanCopilot if… - LeanCopilot is primarily C++; jan is TypeScript. - License: LeanCopilot is MIT, jan is Other. - Tags unique to LeanCopilot: c++, formal-mathematics, lean, lean4. ## When NOT to use jan - - If you require real-time updates to the AI model, since Jan uses static local models which may not get frequent updates. - - When a vast knowledge base or continuous learning capabilities are essential, as Jan's offline nature constrains its ability to stay current with new information. ## When NOT to use LeanCopilot - Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic. - LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. ## Common questions ### What is the difference between jan and LeanCopilot? jan: open source alternative to ChatGPT that runs offline locally. LeanCopilot: LLMs as Copilots for Theorem Proving in Lean. See the comparison table for live GitHub stats and shared categories. ### When should I choose jan over LeanCopilot? Choose jan over LeanCopilot when jan is primarily TypeScript; LeanCopilot is C++; License: jan is Other, LeanCopilot is MIT; Tags unique to jan: chatgpt, gpt, llamacpp, localai; - If you require an offline-capable AI assistant for environments without internet access. ### When should I choose LeanCopilot over jan? Choose LeanCopilot over jan when LeanCopilot is primarily C++; jan is TypeScript; License: LeanCopilot is MIT, jan is Other; Tags unique to LeanCopilot: c++, formal-mathematics, lean, lean4. ### When should I avoid jan? - If you require real-time updates to the AI model, since Jan uses static local models which may not get frequent updates. - When a vast knowledge base or continuous learning capabilities are essential, as Jan's offline nature constrains its ability to stay current with new information. ### When should I avoid LeanCopilot? Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic. LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. ### Is jan or LeanCopilot more popular on GitHub? jan has more GitHub stars (43,499 vs 1,299). Stars measure visibility, not whether either tool fits your constraints. ### Are jan and LeanCopilot open source? Yes - both are open-source projects on GitHub (jan: Other, LeanCopilot: MIT). ### Where can I find alternatives to jan or LeanCopilot? GraphCanon lists graph-backed alternatives at [jan alternatives](/tools/janhq-jan/alternatives) and [LeanCopilot alternatives](/tools/lean-dojo-leancopilot/alternatives) ([jan markdown twin](/tools/janhq-jan/alternatives.md), [LeanCopilot markdown twin](/tools/lean-dojo-leancopilot/alternatives.md)), ranked by typed relationship edges rather than popularity votes. ### Is there a machine-readable version of this comparison? Yes. The markdown twin at [this comparison](/compare/janhq-jan-vs-lean-dojo-leancopilot.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, jan or LeanCopilot? jan: Very active. LeanCopilot: Active. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance. ### Where are the full trust reports for jan and LeanCopilot? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [jan trust report](/tools/janhq-jan/trust); [LeanCopilot trust report](/tools/lean-dojo-leancopilot/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=janhq-jan`](/api/graphcanon/graph?tool=janhq-jan) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_