--- title: "airunner vs FastChat" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/capsize-games-airunner-vs-lm-sys-fastchat" tools: ["capsize-games-airunner", "lm-sys-fastchat"] --- # airunner vs FastChat *GraphCanon updated Jul 12, 2026* ## Verdict Pick airunner when license: airunner is GPL-3.0, FastChat is Apache-2.0; pick FastChat when license: FastChat is Apache-2.0, airunner is GPL-3.0. [airunner](https://airunner.capsizegames.com) reports 1.3k GitHub stars, 99 forks, and 5 open issues, last pushed Jul 8, 2026. [FastChat](https://github.com/lm-sys/FastChat) has 39k stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. Figures are from public GitHub metadata via [airunner's repository](https://github.com/Capsize-Games/airunner) and [FastChat's repository](https://github.com/lm-sys/FastChat). | | [airunner](/tools/capsize-games-airunner.md) | [FastChat](/tools/lm-sys-fastchat.md) | | --- | --- | --- | | Tagline | Offline inference engine for art, real-time voice conversations, LLM powered chatbots and automated workflows | An open platform for training, serving, and evaluating large language models | | Stars | 1,312 | 39,490 | | Forks | 99 | 4,788 | | Open issues | 5 | 1,027 | | Language | Python | Python | | Adopt for | - | FastChat is a comprehensive open platform for managing large language models (LLMs) that includes capabilities for training, serving, evaluating, and comparing chatbot models via web UIs and RESTful APIs. It powers ChatB | | Persona | - | - | | Runtime | - | - | | License | GPL-3.0 | Apache-2.0 | | Categories | Computer Vision, Evaluation & Observability, Inference & Serving, Speech & Audio | Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [airunner](/tools/capsize-games-airunner.md) | [FastChat](/tools/lm-sys-fastchat.md) | | --- | --- | --- | | Maintenance | Very active (96%) | Steady (60%) | | Days since push | 3d | 71d | | Open issues (now) | 5 | 1.0k | | Full report | [trust report](/tools/capsize-games-airunner/trust.md) | [trust report](/tools/lm-sys-fastchat/trust.md) | ## Shared compatibility - **Python**: [airunner](/tools/capsize-games-airunner.md) - Python runtime; [FastChat](/tools/lm-sys-fastchat.md) - Python runtime ## Decision facts: FastChat - **Adopt for:** FastChat is a comprehensive open platform for managing large language models (LLMs) that includes capabilities for training, serving, evaluating, and comparing chatbot models via web UIs and RESTful APIs. It powers ChatB ## Choose when ### Choose airunner if… - License: airunner is GPL-3.0, FastChat is Apache-2.0. - Tags unique to airunner: ai-art, chatbot, deep-learning, image-generation. - Also covers Computer Vision, Speech & Audio. - airunner ships Docker support for self-hosted deployment. ### Choose FastChat if… - License: FastChat is Apache-2.0, airunner is GPL-3.0. - Tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models. - Also covers LLM Frameworks, Model Training. - - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench. ## When NOT to use airunner - Evaluation & Observability: Defer heavyweight eval infra only until you have real traffic - never skip it once users depend on answers. - Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic. ## When NOT to use FastChat - - You require a proprietary or closed-source framework; FastChat is open-source under Apache-2.0 license and its use might be unsuitable for environments requiring proprietary solutions. - - Your chatbot evaluation needs do not align with the types of data used in FastChat's datasets (e.g., human votes, MT-Bench evaluations). - - You prefer a more user-friendly setup without the need to clone a repository and manually install dependencies; FastChat requires installation from source with additional steps for Rust and CMake on - + Mac. ## Common questions ### What is the difference between airunner and FastChat? airunner: Offline inference engine for art, real-time voice conversations, LLM powered chatbots and automated workflows. FastChat: An open platform for training, serving, and evaluating large language models. See the comparison table for live GitHub stats and shared categories. ### When should I choose airunner over FastChat? Choose airunner over FastChat when License: airunner is GPL-3.0, FastChat is Apache-2.0; Tags unique to airunner: ai-art, chatbot, deep-learning, image-generation; Also covers Computer Vision, Speech & Audio; airunner ships Docker support for self-hosted deployment. ### When should I choose FastChat over airunner? Choose FastChat over airunner when License: FastChat is Apache-2.0, airunner is GPL-3.0; Tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models; Also covers LLM Frameworks, Model Training; - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench. ### When should I avoid airunner? Evaluation & Observability: Defer heavyweight eval infra only until you have real traffic - never skip it once users depend on answers. Inference & Serving: Self-hosting rarely beats a hosted API on cost until you have steady, high-volume traffic. ### When should I avoid FastChat? - You require a proprietary or closed-source framework; FastChat is open-source under Apache-2.0 license and its use might be unsuitable for environments requiring proprietary solutions. - Your chatbot evaluation needs do not align with the types of data used in FastChat's datasets (e.g., human votes, MT-Bench evaluations). - You prefer a more user-friendly setup without the need to clone a repository and manually install dependencies; FastChat requires installation from source with additional steps for Rust and CMake on + Mac. ### Is airunner or FastChat more popular on GitHub? FastChat has more GitHub stars (39,490 vs 1,312). Stars measure visibility, not whether either tool fits your constraints. ### Are airunner and FastChat open source? Yes - both are open-source projects on GitHub (airunner: GPL-3.0, FastChat: Apache-2.0). ### Where can I find alternatives to airunner or FastChat? GraphCanon lists graph-backed alternatives at [airunner alternatives](/tools/capsize-games-airunner/alternatives) and [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) ([airunner markdown twin](/tools/capsize-games-airunner/alternatives.md), [FastChat markdown twin](/tools/lm-sys-fastchat/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/capsize-games-airunner-vs-lm-sys-fastchat.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, airunner or FastChat? airunner: Very active. FastChat: Steady. 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 airunner and FastChat? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [airunner trust report](/tools/capsize-games-airunner/trust); [FastChat trust report](/tools/lm-sys-fastchat/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=capsize-games-airunner`](/api/graphcanon/graph?tool=capsize-games-airunner) - 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/_