Hugging Face Transformers

The central model-definition framework for state-of-the-art ML models across text, vision, audio, video, and multimodal tasks. Provides pretrained model weights, tokenizers, pipelines, and training APIs. Interfaces with PyTorch (primary), with 400+ model architectures and 750k+ checkpoints on the Hub. MAJOR VERSION NOTE: v5 released late 2025 — first major release in 5 years. v5 is PyTorch-only (TensorFlow/Flax/JAX removed). pip install transformers installs v5 as of Feb 2026. v4 was the last stable version before this; v4.57.x is the last v4 release. Requires Python 3.10+ in v5.