OneTrainer is a comprehensive training solution for diffusion-based image generation models. It supports full fine-tuning, LoRA, and embedding training methods across multiple model architectures including Stable Diffusion, FLUX, PixArt-Sigma, and others. The framework includes dataset tooling for automatic captioning using vision-language models like BLIP and WD-1.4, masked training for focused learning, EMA support, and integration with TensorBoard for training monitoring.