HuggingFace Transformers
The library that made pretrained transformers trivially loadable — from BERT to Llama — with a consistent API across tasks.
LLM & Agent Frameworks Intermediate
Category
LLM & Agent Frameworks
Difficulty
Intermediate
When to use
Loading, fine-tuning, or running any pretrained transformer model in Python.
When not to use
You're serving at high throughput — reach for vLLM or TensorRT-LLM for inference, transformers is slower.
Alternatives
vLLM llama.cpp ONNX Runtime