--- title: "FastChat vs sad" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/lm-sys-fastchat-vs-lrudl-sad" tools: ["lm-sys-fastchat", "lrudl-sad"] --- # FastChat vs sad *GraphCanon updated Jul 15, 2026* ## Verdict Pick FastChat when fastChat is primarily Python; sad is HTML; pick sad when sad is primarily HTML; FastChat is Python. [FastChat](https://github.com/lm-sys/FastChat) reports 39k GitHub stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. [sad](https://situational-awareness-dataset.org/) has 52 stars, 8 forks, and 4 open issues, last pushed Dec 14, 2024. Figures are from public GitHub metadata via [FastChat's repository](https://github.com/lm-sys/FastChat) and [sad's repository](https://github.com/LRudL/sad). | | [FastChat](/tools/lm-sys-fastchat.md) | [sad](/tools/lrudl-sad.md) | | --- | --- | --- | | Tagline | An open platform for training, serving, and evaluating large language models | Situational Awareness Dataset | | Stars | 39,494 | 52 | | Forks | 4,786 | 8 | | Open issues | 1,027 | 4 | | Language | Python | HTML | | 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 | Apache-2.0 | CC-BY-4.0 | | Categories | Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training | Evaluation & Observability, LLM Frameworks | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [FastChat](/tools/lm-sys-fastchat.md) | [sad](/tools/lrudl-sad.md) | | --- | --- | --- | | Maintenance | Steady (60%) | Dormant (18%) | | Days since push | 74d | 577d | | Open issues (now) | 1.0k | 4 | | Owner type | Organization | User | | Full report | [trust report](/tools/lm-sys-fastchat/trust.md) | [trust report](/tools/lrudl-sad/trust.md) | ## Shared compatibility - **Python**: [FastChat](/tools/lm-sys-fastchat.md) - Python runtime; [sad](/tools/lrudl-sad.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 FastChat if… - FastChat is primarily Python; sad is HTML. - License: FastChat is Apache-2.0, sad is CC-BY-4.0. - Tags unique to FastChat: chatbots, distributed-serving, evaluation system, large-language-models. - Also covers Inference & Serving, Model Training. - - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench. ### Choose sad if… - sad is primarily HTML; FastChat is Python. - License: sad is CC-BY-4.0, FastChat is Apache-2.0. - Tags unique to sad: html, llm-evaluation, ml. ## 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. ## When NOT to use sad - Last GitHub push was 578 days ago (dormant maintenance, Dec 14, 2024). Validate activity before betting a new project on sad. - Evaluation & Observability: Defer heavyweight eval infra only until you have real traffic - never skip it once users depend on answers. - 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 FastChat and sad? FastChat: An open platform for training, serving, and evaluating large language models. sad: Situational Awareness Dataset. See the comparison table for live GitHub stats and shared categories. ### When should I choose FastChat over sad? Choose FastChat over sad when FastChat is primarily Python; sad is HTML; License: FastChat is Apache-2.0, sad is CC-BY-4.0; Tags unique to FastChat: chatbots, distributed-serving, evaluation system, large-language-models; Also covers Inference & Serving, Model Training; - You are looking to train and evaluate state-of-the-art models such as Vicuna or MT-Bench. ### When should I choose sad over FastChat? Choose sad over FastChat when sad is primarily HTML; FastChat is Python; License: sad is CC-BY-4.0, FastChat is Apache-2.0; Tags unique to sad: html, llm-evaluation, ml. ### 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. ### When should I avoid sad? Last GitHub push was 578 days ago (dormant maintenance, Dec 14, 2024). Validate activity before betting a new project on sad. Evaluation & Observability: Defer heavyweight eval infra only until you have real traffic - never skip it once users depend on answers. LLM Frameworks: Avoid a framework for a single prompt-and-retrieve call; the abstraction can cost more than it saves. ### Is FastChat or sad more popular on GitHub? FastChat has more GitHub stars (39,494 vs 52). Stars measure visibility, not whether either tool fits your constraints. ### Are FastChat and sad open source? Yes - both are open-source projects on GitHub (FastChat: Apache-2.0, sad: CC-BY-4.0). ### Where can I find alternatives to FastChat or sad? GraphCanon lists graph-backed alternatives at [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) and [sad alternatives](/tools/lrudl-sad/alternatives) ([FastChat markdown twin](/tools/lm-sys-fastchat/alternatives.md), [sad markdown twin](/tools/lrudl-sad/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/lm-sys-fastchat-vs-lrudl-sad.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, FastChat or sad? FastChat: Steady. sad: Dormant. 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 FastChat and sad? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [FastChat trust report](/tools/lm-sys-fastchat/trust); [sad trust report](/tools/lrudl-sad/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=lm-sys-fastchat`](/api/graphcanon/graph?tool=lm-sys-fastchat) - 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/_