Stable Diffusion 3.5 is offered here in two sizes. Medium is the 2.5-billion-parameter model built on the improved MMDiT-X architecture; Large generates high-resolution images with fine detail and, thanks to query-key normalisation, produces diverse outputs from the same prompt.

When to choose Stable Diffusion

Choose Stable Diffusion when you want the open, widely documented baseline that most community tooling assumes. Flux and SDXL are the neighbouring open families with different strengths.

Choosing between the variants

Medium is the cheaper, faster model and enough for most prompts. Large is the one for high-resolution work and for when you want several genuinely different takes on one prompt.

* FREQUENTLY ASKED

About Stable Diffusion

How large is the Medium model?: 2.5 billion parameters, built on the improved MMDiT-X architecture introduced with the 3.5 release.
Why does Large give more varied results?: Query-key normalisation in its architecture produces more diverse outputs from the same prompt rather than near-identical repeats.
Which supports more artistic styles?: Both handle a wide range, but Large holds fine detail better at high resolution, which shows most in complex illustrative work.