FastChat vs. Kimi

Overview

FastChat is the open platform for training, serving, and evaluating LLM chatbots developed and maintained by LMSYS.

FastChat is an open-source library for training, serving, and evaluating LLM chat systems from LMSYS. It includes training and evaluation code, a model serving system, a Web GUI, and a finetuning pipeline, and is the de facto system for Vicuna as well as FastChat-T5. FastChat also includes the Chatbot Arena for benchmarking LLMs.

Initial release: 2023-04-28

Reference

https://github.com/lm-sys/FastChat

Further Reading

• https://chat.lmsys.org/
• https://lmsys.org/projects/

Overview

Kimi is Moonshot AI's open-weight family for long-context reasoning, coding, multimodal agents, and research. Kimi K3 is the current generation.

Moonshot AI launched Kimi in 2023 with an early focus on long-context document understanding. Kimi K3, released in July 2026, is a 2.8T-parameter mixture-of-experts model with 104B active parameters. It combines native vision, a one-million-token context window, long-horizon coding, knowledge work, reasoning, and agent orchestration. The full model weights are available under the Kimi K3 License.

Initial release: 2023-10-09

Current generation: Kimi K3

Reference

https://huggingface.co/moonshotai/Kimi-K3

Further Reading

• https://github.com/MoonshotAI/Kimi-K2
• https://github.com/MoonshotAI/Kimi-K3
• https://huggingface.co/moonshotai/Kimi-K3