LMSYS-Chat-1M
One million real conversations between users and 25 different state-of-the-art LLMs collected from Chatbot Arena. Invaluable for understanding real-world usage patterns, language diversity, and human preferences — spans 154 languages and covers everyday tasks, creative writing, coding, and more.
from datasets import load_dataset
ds = load_dataset("lmsys/lmsys-chat-1m")Preview a sample row
{
"conversation_id": "abc123",
"model": "gpt-4",
"conversation": [
{"role": "user", "content": "Can you help me debug this Python code?"},
{"role": "assistant", "content": "I'd be happy to help! Please paste the code and describe the error."}
],
"language": "English"
}Fine-tune with this dataset
Estimated VRAM to fine-tune with QLoRA (4-bit base model + LoRA adapters), using conservative defaults:
New to fine-tuning? Follow the step-by-step walkthrough: Fine-Tune Your First LLM in 1 Hour
Frequently asked questions
Can I use LMSYS-Chat-1M commercially?
Not in a product — LMSYS-Chat-1M is released under CC BY-NC 4.0, which restricts use to research and other non-commercial purposes. For commercial fine-tuning, pick a permissively licensed dataset from the same category instead.
How much data does LMSYS-Chat-1M contain, and do I need all of it?
LMSYS-Chat-1M contains 1M Conversations. You rarely need all of it: for style and format fine-tuning, a few hundred to a few thousand examples are enough — load a slice (e.g. split="train[:1000]") and scale up only if quality plateaus.
What is LMSYS-Chat-1M best used for?
Studying real-world usage patterns across 25 models (non-commercial). It belongs to the Instruction / SFT section of our dataset hub, where you'll find alternatives and complementary sets.