OpenAI has launched two smaller versions of its latest GPT-5.4 model—Mini and Nano—designed for developers who prioritize speed and cost over maximum reasoning power. The Mini model runs more than twice as fast as the full model while staying close on key benchmarks, and the Nano model focuses on simple classification and data‑extraction tasks. Both models support text and image inputs, tool use, function calling, and a 400,000‑token context window, and they are available today via the API, Codex, and ChatGPT. This tiered approach lets developers allocate cheaper models for routine work and reserve the full model for complex reasoning, reshaping how real‑time AI applications are built. Read more →