SHSelfHostIndex

FastChat vs OpenLLM

A side-by-side comparison of two self-hosted local llm runners options — licensing, setup difficulty, resource needs, and what each one replaces.

Not the right match-up?
FA FastChat Platform for serving and evaluating large language models VS OP OpenLLM Run any open LLM as an OpenAI-compatible API endpoint
FeatureFastChatOpenLLM
Deploy effortUnder-an-hour setupUnder-an-hour setup
Health score69 · Good81 · Excellent
CategoryLocal LLM RunnersLocal LLM Runners
LicenseApache-2.0Apache-2.0
LanguagePythonPython
Setup difficultyHardMedium
Min. RAM8,192 MB8,192 MB
Deploymentdocker, sourcedocker, kubernetes, bare-metal
GitHub stars★ 39,550★ 12,547
First released20232023
ReplacesOpenAI APIOpenAI API

What are FastChat and OpenLLM?

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

Read the full FastChat guide →

OpenLLM

OpenLLM lets developers run open-source large language models as OpenAI-compatible API endpoints with a single command. It is built on BentoML and supports streaming, quantization, and easy deployment.

  • One-command model serving
  • OpenAI-compatible API
  • Built-in chat UI
  • Cloud deployment via BentoML

FastChat vs OpenLLM: key differences

Both projects are written in Python. FastChat has the considerably larger community, at 39,550 GitHub stars versus 12,547.

Why pick each one

Choose FastChat if…

  • OpenAI-compatible API
  • Powers Chatbot Arena
  • Multi-model serving

Watch out for

  • GPU recommended
  • Steep learning curve
FastChat details

Choose OpenLLM if…

  • Released under the Apache-2.0 license
  • First-class Docker support for quick deployment
  • Kubernetes-ready with Helm charts available
  • Mature project with 12.5k GitHub stars
OpenLLM details

Frequently asked questions

Is FastChat or OpenLLM better?

Neither is universally better. FastChat has the larger community, while OpenLLM is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.

Are FastChat and OpenLLM free and open-source?

Yes. FastChat is licensed under Apache-2.0 and OpenLLM under Apache-2.0. Both can be self-hosted at no software cost.

Can I run FastChat and OpenLLM with Docker?

FastChat: yes. OpenLLM: yes.

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