OpenChat (8,984 Stars) 2026: The Open-Source Chatbot Model Family You Can Fine-Tune and Run Locally

OpenChat (8,984 stars) is an open-source family of chatbot models known for strong performance with mixed data training. Here is how to run and fine-tune them.

💡 What You Will Learn

OpenChat (8,984 stars) is an open-source family of chatbot models known for strong performance with mixed data training. Here is how to run and fine-tune them.

📜 Table of Contents

• The short answer
• Why OpenChat got attention
• Run it locally
• Fine-tuning notes
• FAQ

The short answer

togethercomputer/OpenChat (8,984 stars, Python) is an open-source library and model family for training and running chatbot models. It pioneered the "mixed" training approach - combining instruction data, preference data, and general conversation - which produced models that punch above their weight class.

Why OpenChat got attention

• Strong small models: OpenChat-3.5 (7B) scored competitively against much larger models on many benchmarks
• Simple training recipe: the mixed-data fine-tuning approach is documented and reproducible
• Easy serving: OpenAI-compatible API server included
• Local friendly: 7B models run on consumer GPUs

Run it locally

Option 1 - via Transformers (163,376 stars):

from transformers import AutoModelForCausalLM, AutoTokenizer
tokenizer = AutoTokenizer.from_pretrained("openchat/openchat-3.5-1210")
model = AutoModelForCausalLM.from_pretrained("openchat/openchat-3.5-1210", torch_dtype="auto")

Option 2 - serve with the built-in API:

git clone https://github.com/imoneoi/openchat.git
cd openchat && pip install -e .
python -m openchat.server --model openchat/openchat-3.5-1210
# OpenAI-compatible endpoint at http://localhost:18888

Fine-tuning notes

• The repo provides a finetune script with the exact data mix used for OpenChat-3.5.
• LoRA-style efficient fine-tuning is supported for consumer GPUs.
• Start from the 7B base and evaluate on your task before scaling up.

FAQ

Is it free? Yes - the models and training code are open source (Apache-2.0 for the code).

Can I use it commercially? Check each model card license; base model licenses vary.

How does it compare to Llama? OpenChat is often trained on top of Llama/Mistral bases, adding its mixed-data recipe - performance depends on the base model.

❓ FAQ

Is it free?

Yes - the models and training code are open source (Apache-2.0 for the code).

Can I use it commercially?

Check each model card license; base model licenses vary.

How does it compare to Llama?

OpenChat is often trained on top of Llama/Mistral bases, adding its mixed-data recipe - performance depends on the base model.