--- title: "FastChat vs LongCite" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/lm-sys-fastchat-vs-thudm-longcite" tools: ["lm-sys-fastchat", "thudm-longcite"] --- # FastChat vs LongCite *GraphCanon updated Jul 11, 2026* ## Verdict Pick FastChat when tags unique to FastChat: chatbots, distributed serving, evaluation system, large-language-models; pick LongCite when tags unique to LongCite: benchmark, citation-generation, fine-tuning, llm. [FastChat](https://github.com/lm-sys/FastChat) reports 39k GitHub stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. [LongCite](https://github.com/THUDM/LongCite) has 520 stars, 30 forks, and 9 open issues, last pushed Dec 31, 2024. Figures are from public GitHub metadata via [FastChat's repository](https://github.com/lm-sys/FastChat) and [LongCite's repository](https://github.com/THUDM/LongCite). | | [FastChat](/tools/lm-sys-fastchat.md) | [LongCite](/tools/thudm-longcite.md) | | --- | --- | --- | | Tagline | An open platform for training, serving, and evaluating large language models | LongCite: Enabling LLMs to Generate Fine-grained Citations in Long-context QA | | Stars | 39,490 | 520 | | Forks | 4,788 | 30 | | Open issues | 1,027 | 9 | | 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 | Apache-2.0 | Apache-2.0 | | 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) | [LongCite](/tools/thudm-longcite.md) | | --- | --- | --- | | Maintenance | Steady (60%) | Dormant (18%) | | Days since push | 71d | 557d | | Open issues (now) | 1.0k | 9 | | Full report | [trust report](/tools/lm-sys-fastchat/trust.md) | [trust report](/tools/thudm-longcite/trust.md) | ## 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… - 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 LongCite if… - Tags unique to LongCite: benchmark, citation-generation, fine-tuning, llm. - Leaner open-issue backlog (9). ## 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 LongCite - Last GitHub push was 558 days ago (dormant maintenance, Dec 31, 2024). Validate activity before betting a new project on LongCite. - 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 LongCite? FastChat: An open platform for training, serving, and evaluating large language models. LongCite: LongCite: Enabling LLMs to Generate Fine-grained Citations in Long-context QA. See the comparison table for live GitHub stats and shared categories. ### When should I choose FastChat over LongCite? Choose FastChat over LongCite when 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 LongCite over FastChat? Choose LongCite over FastChat when Tags unique to LongCite: benchmark, citation-generation, fine-tuning, llm; Leaner open-issue backlog (9). ### 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 LongCite? Last GitHub push was 558 days ago (dormant maintenance, Dec 31, 2024). Validate activity before betting a new project on LongCite. 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 LongCite more popular on GitHub? FastChat has more GitHub stars (39,490 vs 520). Stars measure visibility, not whether either tool fits your constraints. ### Are FastChat and LongCite open source? Yes - both are open-source projects on GitHub (FastChat: Apache-2.0, LongCite: Apache-2.0). ### Where can I find alternatives to FastChat or LongCite? GraphCanon lists graph-backed alternatives at [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) and [LongCite alternatives](/tools/thudm-longcite/alternatives) ([FastChat markdown twin](/tools/lm-sys-fastchat/alternatives.md), [LongCite markdown twin](/tools/thudm-longcite/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-thudm-longcite.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, FastChat or LongCite? FastChat: Steady. LongCite: 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 LongCite? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [FastChat trust report](/tools/lm-sys-fastchat/trust); [LongCite trust report](/tools/thudm-longcite/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/_