Verified project record

Lightning-AI/litgpt

litgpt enables developers to pretrain, finetune, and deploy 20+ high-performance large language models with optimized performance and proven recipes. It provides from-scratch implementations with no heavy abstractions, giving developers full control over the entire model lifecycle.

Project overview

litgpt stands out by offering from-scratch implementations of 20+ high-performance LLMs without internal abstractions, packaged with proven recipes for pretraining, finetuning, and deployment under an Apache 2.0 license for unlimited enterprise use.

Project type: Model Development · Model Runtime · Infrastructure
Deployment: Refer to project documentation
License: Apache-2.0

Best for

Developers who want full control over model internals with no hidden abstractions
AI engineers and researchers who need to pretrain, finetune, evaluate, quantize, and deploy LLMs using a unified CLI-driven workflow
Enterprise teams that need an Apache 2.0 licensed solution for unlimited commercial use

Key capabilities

Pretrain AI models from scratch on custom text data via CLI commands
Finetune pretrained models using methods like LoRA, QLoRA, and Adapter on custom datasets
Serve models via an automatically configured web server that can be queried via API
Evaluate models on tasks like MMLU and Truthful QA via CLI
Lower memory requirements using 4-bit floats, 8-bit integers, and double quantization
Test models via an interactive chat interface directly in the CLI

Limitations and risks

Large models and training workflows require significant GPU resources to run effectively.
Scaling to large models such as 70B+ parameters requires multi-GPU clusters, incurring high infrastructure costs.

Getting started

Install litgpt quickly via pip using pip install 'litgpt[extra]', then immediately test a model by running litgpt chat microsoft/phi-2. The CLI provides simple commands for all major workflows.

Evidence and sources

GitHub project description: 20+ high-performance LLMs with recipes to pretrain, finetune and deploy at scale.
README: ✅ From scratch implementations ✅ No abstractions ✅ Beginner friendly
README: Every LLM is implemented from scratch with **no abstractions** and **full control**, making them blazing fast, minimal, and performant at enterprise scale.
README: ✅ **Enterprise ready -** Apache 2.0 for unlimited enterprise use.
README: pip install 'litgpt[extra]'

Reviewed at: 2026-07-17T23:49:27Z