--- title: "ChainForge vs FastChat" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/ianarawjo-chainforge-vs-lm-sys-fastchat" tools: ["ianarawjo-chainforge", "lm-sys-fastchat"] --- # ChainForge vs FastChat *GraphCanon updated Aug 20, 2026* ## Verdict Pick ChainForge if web-based visual programming tool for prompt testing on LLMs; supports local installation and Docker for advanced feature access; pick FastChat if 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. [ChainForge](https://chainforge.ai/docs) reports 3.0k GitHub stars, 256 forks, and 70 open issues, last pushed Jun 10, 2026. [FastChat](https://github.com/lm-sys/FastChat) has 40k stars, 4.8k forks, and 1.0k open issues, last pushed May 1, 2026. Figures are from public GitHub metadata via [ChainForge's repository](https://github.com/ianarawjo/ChainForge) and [FastChat's repository](https://github.com/lm-sys/FastChat). | | [ChainForge](/tools/ianarawjo-chainforge.md) | [FastChat](/tools/lm-sys-fastchat.md) | | --- | --- | --- | | Tagline | An open-source visual programming environment for battle-testing prompts to LLMs. | An open platform for training, serving, and evaluating large language models | | Stars | 3,027 | 39,517 | | Forks | 256 | 4,788 | | Open issues | 70 | 1,038 | | Language | TypeScript | Python | | Adopt for | Web-based visual programming tool for prompt testing on LLMs; supports local installation and Docker for advanced feature access. | 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 | MIT | Apache-2.0 | | Categories | Evaluation & Observability, LLM Frameworks | Evaluation & Observability, Inference & Serving, LLM Frameworks, Model Training | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [ChainForge](/tools/ianarawjo-chainforge.md) | [FastChat](/tools/lm-sys-fastchat.md) | | --- | --- | --- | | Maintenance | Steady (60%) | Slowing (36%) | | Days since push | 70d | 98d | | Open issues (now) | 70 | 1.0k | | Stars delta | +14 (30d) | Unknown | | Open issues delta | +1 (30d) | Unknown | | Owner type | User | Organization | | Full report | [trust report](/tools/ianarawjo-chainforge/trust.md) | [trust report](/tools/lm-sys-fastchat/trust.md) | ## Shared compatibility - **Python**: [ChainForge](/tools/ianarawjo-chainforge.md) - Python runtime; [FastChat](/tools/lm-sys-fastchat.md) - Python runtime ## Decision facts: ChainForge - **Adopt for:** Web-based visual programming tool for prompt testing on LLMs; supports local installation and Docker for advanced feature access. ## 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 ChainForge if… - ChainForge is primarily TypeScript; FastChat is Python. - License: ChainForge is MIT, FastChat is Apache-2.0. - Tags unique to ChainForge: ai, evaluation, llmops, prompt-engineering. - ChainForge ships Docker support for self-hosted deployment. - Need extensive features beyond web limitations ### Choose FastChat if… - FastChat is primarily Python; ChainForge is TypeScript. - License: FastChat is Apache-2.0, ChainForge is MIT. - Tags unique to FastChat: chatbots, distributed-serving, evaluation system. - 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 NOT to use ChainForge - Looking for a solution without local setup or Docker support - Prefer not managing API keys via environment variable configuration ## 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 ChainForge and FastChat? ChainForge: An open-source visual programming environment for battle-testing prompts to LLMs.. 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 ChainForge over FastChat? Choose ChainForge over FastChat when ChainForge is primarily TypeScript; FastChat is Python; License: ChainForge is MIT, FastChat is Apache-2.0; Tags unique to ChainForge: ai, evaluation, llmops, prompt-engineering; ChainForge ships Docker support for self-hosted deployment; Need extensive features beyond web limitations. ### When should I choose FastChat over ChainForge? Choose FastChat over ChainForge when FastChat is primarily Python; ChainForge is TypeScript; License: FastChat is Apache-2.0, ChainForge is MIT; Tags unique to FastChat: chatbots, distributed-serving, evaluation system; 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 avoid ChainForge? Looking for a solution without local setup or Docker support Prefer not managing API keys via environment variable configuration ### 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 ChainForge or FastChat more popular on GitHub? FastChat has more GitHub stars (39,517 vs 3,027). Stars measure visibility, not whether either tool fits your constraints. ### Are ChainForge and FastChat open source? Yes - both are open-source projects on GitHub (ChainForge: MIT, FastChat: Apache-2.0). ### Where can I find alternatives to ChainForge or FastChat? GraphCanon lists graph-backed alternatives at [ChainForge alternatives](/tools/ianarawjo-chainforge/alternatives) and [FastChat alternatives](/tools/lm-sys-fastchat/alternatives) ([ChainForge markdown twin](/tools/ianarawjo-chainforge/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/ianarawjo-chainforge-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, ChainForge or FastChat? ChainForge: Steady. FastChat: Slowing. 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 ChainForge and FastChat? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [ChainForge trust report](/tools/ianarawjo-chainforge/trust); [FastChat trust report](/tools/lm-sys-fastchat/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=ianarawjo-chainforge`](/api/graphcanon/graph?tool=ianarawjo-chainforge) - 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/_