FastChat vs ik_llama.cpp
A side-by-side comparison of two self-hosted local llm runners options — licensing, setup difficulty, resource needs, and what each one replaces.
| Feature | FastChat | ik_llama.cpp |
|---|---|---|
| Deploy effort | Under-an-hour setup | Read-the-docs project |
| Health score | 69 · Good | 85 · Excellent |
| Category | Local LLM Runners | Local LLM Runners |
| License | Apache-2.0 | MIT |
| Language | Python | C++ |
| Setup difficulty | Hard | Hard |
| Min. RAM | 8,192 MB | 8,192 MB |
| Deployment | docker, source | source, binary |
| GitHub stars | ★ 39,550 | ★ 3,254 |
| First released | 2023 | 2024 |
| Replaces | OpenAI API | OpenAI API |
What are FastChat and ik_llama.cpp?
FastChat
FastChat is an open platform for training, serving, and evaluating large language model chatbots. It powers the Chatbot Arena and provides an OpenAI-compatible API server for self-hosted models.
- OpenAI-compatible API
- Web UI for model chat
- Distributed serving
- Model evaluation tools
ik_llama.cpp
ik_llama.cpp is a fork of llama.cpp maintained by ikawrakow that adds optimized CPU and CUDA kernels, additional quantization formats, and improved performance for mixture-of-experts models. It targets users running large local models on commodity hardware.
- New quantization types
- Optimized MoE inference
- CPU and CUDA kernels
- OpenAI-compatible server
FastChat vs ik_llama.cpp: key differences
FastChat is written in Python, while ik_llama.cpp is built with C++. Licensing differs — Apache-2.0 for FastChat versus MIT for ik_llama.cpp. FastChat has the considerably larger community, at 39,550 GitHub stars versus 3,254. FastChat lists first-class Docker deployment; ik_llama.cpp does not.
Why pick each one
Choose FastChat if…
- OpenAI-compatible API
- Powers Chatbot Arena
- Multi-model serving
Watch out for
- GPU recommended
- Steep learning curve
Choose ik_llama.cpp if…
- Released under the MIT license
- Active community (3.3k GitHub stars)
- Written in C++
Frequently asked questions
Is FastChat or ik_llama.cpp better?
Neither is universally better. FastChat has the larger community; both share a hard setup difficulty, so the decision comes down to features and licensing.
Are FastChat and ik_llama.cpp free and open-source?
Yes. FastChat is licensed under Apache-2.0 and ik_llama.cpp under MIT. Both can be self-hosted at no software cost.
Can I run FastChat and ik_llama.cpp with Docker?
FastChat: yes. ik_llama.cpp: check the project docs for container support.