DiffusionGemma Technical Report

[Submitted connected 31 Jul 2026]

View PDF HTML (experimental)

Abstract:We present DiffusionGemma, an experimental open-weight connection exemplary that uses discrete diffusion to make matter astatine exceptionally precocious speed. Rather than decoding 1 token astatine a time, DiffusionGemma iteratively refines blocks of 256 tokens successful parallel, avoiding the sequential decoding bottleneck of accepted autoregressive (AR) ample connection models. Instead of training from scratch, we get DiffusionGemma by fine-tuning the mixture-of-experts Gemma 4 exemplary pinch 3.8B activated and 25.2B full parameters. Our compute-efficient two-stage training pipeline uses less than 10% of the starting AR model's full training token budget. The first shape uses supervised fine-tuning to thatch bidirectional denoising, while the 2nd shape combines reinforcement learning pinch sampler distillation to jointly amended procreation value and conclusion efficiency. DiffusionGemma establishes a caller Pareto frontier for the trade-off betwixt procreation velocity and exemplary capability. Averaged crossed our afloat information suite, it generates astir 20 tokens per guardant walk and achieves astir 1,500 output tokens per 2nd connected a azygous NVIDIA H100 GPU, which is substantially faster than AR models moreover pinch state-of-the-art speculative decoding. DiffusionGemma besides retains the starting model's support for reasoning mode, multimodal inputs, and agelong contexts. Despite diffusion fine-tuning, it remains tin of AR procreation pinch only insignificant capacity degradation, suggesting a way toward hybrid diffusion-AR decoding.