GPT-5.4 mini and nano now available — OpenAI’s most capable small models yet

GPT-5.4-mini is great for spinning up new sub-agents.

x.com

dominik kundel

@dkundel

GPT-5.4-mini is a wildly capable model and gives you ~3.3x more usage on Codex tasks compared to GPT-5.4. It's excellent for spinning up new subagents! pic.x.com/OX8GtEMevR x.com/OpenAI/status/…

OpenAI @OpenAI

GPT-5.4 mini is available today in ChatGPT, Codex, and the API. Optimized for coding, computer use, multimodal understanding, and subagents. And it’s 2x faster than GPT-5 mini. https://t.co/DKh2cC5S3F https://t.co/sirArgn37L

5:09 PM - 17 Mar 2026 270 6