Prefill & Decode Trend 2026

In AI inference, prefill and decode define the two-phase process of text generation. Prefill rapidly processes the entire input prompt in parallel to build the key-value cache, while decode generates output tokens one-by-one, sequentially. This architecture is crucial for optimizing performance and reducing latency. It directly benefits developers building LLM applications and engineers deploying chatbots, code assistants, and search tools, enabling faster, more efficient responses.