LLM Training Dataset Hub
47 curated open datasets for fine-tuning and training LLMs — instruction tuning, reasoning traces, function calling, preference data, and more. Every entry includes the exact license, size, and a load_dataset() snippet.
Instruction / SFT
18Instruction datasets (SFT sets) are prompt–response pairs used for supervised fine-tuning — the first and most important step in teaching a base model to follow instructions, answer in your format, or adopt a specific tone. They range from 1k hand-written examples (LIMA) to multi-million-sample synthetic mixtures (Infinity-Instruct).
Reasoning
6Reasoning datasets store full chains of thought — the step-by-step "thinking" that leads to an answer — rather than just final responses. Fine-tuning on traces distilled from strong reasoning models (DeepSeek R1, QwQ) is how small local models learn to work through math, code, and science problems before answering.
Agentic & Function Calling
3Agentic datasets teach a model to call functions and tools: read a JSON schema, decide when a call is needed, emit valid arguments, and use the result. This is the core skill behind local AI agents — and it must be trained explicitly, because general chat data won't produce reliable tool calls.
Preference (RLHF / DPO)
5Preference datasets contain a prompt plus ranked or scored responses — a chosen answer and a rejected one. They power RLHF, reward models, and DPO: the post-SFT step that teaches a model which of two plausible answers humans actually prefer. Run these after an instruction-tuning pass, not instead of it.
Pretraining
4Pretraining corpora are massive raw-text collections — trillions of tokens of filtered web text, textbooks, and code — used to train base models from scratch or continue pretraining on a new language or domain. You won't fine-tune on these with a consumer GPU, but they define what open base models know.
Multilingual
1Multilingual datasets bring instruction-following and pretraining quality to languages beyond English — from human-annotated instruction pairs in 65 languages (Aya) to quality-filtered web text in 1,000+ languages (FineWeb 2). Essential if your users don't prompt in English.
Code
3Code datasets range from massive permissively-licensed source corpora (The Stack v2) to instruction pairs synthesized from real open-source code. Use them to specialize a model for your stack, improve completion quality, or train a local coding assistant.
Vision
1Vision (multimodal) datasets pair images with text instructions so language models learn to see. LLaVA-style instruction sets are the standard recipe for adding image understanding to an open LLM.
Evaluation & Benchmarks
6Evaluation sets are benchmarks — MMLU, HumanEval, SWE-bench — used to measure models, not to train them. Never mix them into training data: benchmark contamination inflates scores and is the first thing careful reviewers check for.
How to choose a dataset
Match the dataset to the task, not the other way around. Teaching a model to follow instructions or adopt your tone? Use an instruction/SFT set — start with No Robots (human-written) or Dolly 15k (commercial-safe). Improving how a model ranks and phrases answers? You need a preference set for DPO: UltraFeedback is the default choice, HelpSteer2 adds fine-grained quality ratings.
Building a math or coding "thinking" model? Fine-tune on reasoning traces: OpenThoughts3 for breadth, NuminaMath for math, OpenCodeReasoning for code. Making an agent that calls APIs? Function calling is its own skill — Glaive v2 for the basics, xLAM when precision matters. Non-English users? Aya for instructions, FineWeb 2 for continued pretraining.
Two rules save the most time: check the license before you train (CC BY-NC sets can't ship in a commercial product), and start smaller than you think — 1,000 good examples beat 100,000 noisy ones. When in doubt, follow the one-hour walkthrough in Fine-Tune Your First LLM, which uses these exact datasets.
Frequently asked questions
What dataset should I use to fine-tune a chatbot?
Start with an instruction/SFT set. No Robots (10k human-written examples) is the cleanest first dataset, and Databricks Dolly 15k is a commercially safe alternative. For multi-turn chat behavior add UltraChat or WildChat, then refine tone with a preference dataset like UltraFeedback using DPO.
What's the difference between SFT and DPO datasets?
SFT datasets contain prompt–response pairs the model learns to imitate (supervised fine-tuning). DPO and preference datasets contain a prompt plus a chosen and a rejected answer, and the model learns to prefer the better one. Typical pipelines run SFT first, then DPO — for example Tulu 3 SFT followed by UltraFeedback.
Can I use Alpaca commercially?
No — Stanford Alpaca is released under CC BY-NC 4.0, a non-commercial license, because it was generated with OpenAI's text-davinci-003. For commercial fine-tuning use Databricks Dolly 15k (CC BY-SA 3.0), Tulu 3 SFT Mix (ODC-BY), or OpenHermes 2.5 (MIT) instead.
How big should my fine-tuning dataset be?
Quality beats quantity. LIMA showed 1,000 curated examples can align a 65B model, and s1K did the same for reasoning with 1k samples. For style and format changes, 200–1,000 good examples usually suffice; for new domain skills, aim for 10k–100k. Start small and evaluate before scaling.
What is a reasoning-trace dataset?
A reasoning-trace dataset stores not just final answers but the full chain of thought — the step-by-step thinking before each solution. Fine-tuning on traces (OpenThoughts3, NuminaMath-CoT, OpenCodeReasoning) distills reasoning ability from large models into small local ones, which then "think" before they answer.
Which datasets work with Unsloth?
Any dataset here in a standard format works with Unsloth after light formatting: Alpaca-style (instruction/output columns), ShareGPT-style (conversations), or ChatML messages. Popular Unsloth starters are No Robots, Alpaca, and Dolly 15k — our one-hour fine-tuning guide shows how to load them with SFTTrainer on a 6GB GPU.