OpenAI releases GPT-5.4 mini and nano, its ‘most capable small models yet’

OpenAI continues to ship new models with the release of GPT-5.4 mini and nano, its “most capable small models yet.” ChatGPT users can start using GPT-5.4 mini today.

These flavors of GPT-5.4 are designed to be fast and efficient for high-volume workloads, according to OpenAI.

Here’s more about GPT-5.4 mini:

GPT‑5.4 mini significantly improves over GPT‑5 mini across coding, reasoning, multimodal understanding, and tool use, while running more than 2x faster. It also approaches the performance of the larger GPT‑5.4 model on several evaluations, including SWE-Bench Pro and OSWorld-Verified.

And here are more details about GPT-5.4 nano:

GPT‑5.4 nano is the smallest, cheapest version of GPT‑5.4 for tasks where speed and cost matter most. It is also a significant upgrade over GPT‑5 nano. We recommend it for classification, data extraction, ranking, and coding subagents that handle simpler supporting tasks.

GPT-5.4 mini is available starting today in ChatGPT, Codex, and OpenAI’s API.

In ChatGPT, GPT‑5.4 mini is available to Free and Go users via the “Thinking” feature in the + menu. For all other users, GPT‑5.4 mini is available as a rate limit fallback for GPT‑5.4 Thinking.

GPT-5.4 nano is available through the API. You can dig in to how the new models are better at coding, agentic workflows, and computer use here.

OpenAI released GPT-5.4 Thinking with six key improvements earlier this month. GPT-5.3 Instant also arrived in March, promising to be less cringe.

Back in February, OpenAI released its Codex development app for Mac.