OpenAI has launched GPT-5.4 mini and GPT-5.4 nano, its most capable small models to date, designed to bring the strengths of its flagship GPT-5.4 to high-volume, latency-sensitive workloads at a fraction of the cost.
What Are GPT-5.4 Mini and Nano?
These are compact, highly efficient versions of OpenAI's GPT-5.4 model, optimised for speed and cost rather than maximum capability. Think of them as the workhorses of the GPT-5.4 family - not built to replace the full model, but to handle the fast, repetitive, and supporting tasks that make up the bulk of real-world AI workflows.
GPT-5.4 mini is a significant upgrade over its predecessor, GPT-5 mini, with improvements across coding, reasoning, multimodal understanding, and tool use - while running more than 2x faster. In benchmarks, it approaches GPT-5.4-level pass rates at considerably lower latency, making it one of the strongest performance-per-speed tradeoffs available for coding workflows.
GPT-5.4 nano is the smallest and cheapest model in the GPT-5.4 family, purpose-built for tasks where speed and cost matter most, such as classification, data extraction, ranking, and simpler coding subtasks.
GPT-5.4 mini and GPT-5.4 nano: Availability and pricing
GPT-5.4 mini is available today via the API, Codex, and ChatGPT. In Codex, it uses only 30 percent of the GPT-5.4 quota. In ChatGPT, Free and Go users can access it through the Thinking feature, while it serves as a rate-limit fallback for GPT-5.4 Thinking on other plans. GPT-5.4 nano is available in the API for tasks requiring maximum efficiency.
The models are built for developers and businesses running applications where response time shapes the user experience - coding assistants, computer-using systems, multimodal apps that process images in real time, and multi-agent pipelines. OpenAI's own Codex platform demonstrates the intended use: GPT-5.4 handles planning and coordination while GPT-5.4 mini subagents work in parallel on narrower tasks like searching a codebase or reviewing files.
The launch follows OpenAI's release of GPT-5.4 earlier this month, which introduced mid-response course correction, improved deep web research, and enhanced long-context reasoning.
