Seed Diffusion Preview: How ByteDance’s Discrete Diffusion Model Achieves 5.4x Faster Code Generation

Code at the Speed of Thought: Inside ByteDance’s Seed Diffusion Preview July 31, 2025 – ByteDance Seed Team Imagine typing a one-sentence prompt and receiving 2,000+ usable lines of Python in under a second—without sacrificing correctness. That is exactly what ByteDance’s new experimental model, Seed Diffusion Preview, delivered on eight open code benchmarks. 1. Why Can a Diffusion Model Write Code So Fast? Let us start with the basics. Approach Generates Tokens Typical Speed on H20 GPU Order Flexibility Autoregressive (AR) One by one, left-to-right ~400 tokens / s Strictly sequential Discrete Diffusion All tokens in parallel 2,146 tokens / …