OpenAI on Wednesday announced the release of GPT-5.4 mini and GPT-5.4 nano, extending the capabilities of its flagship GPT-5.4 model to faster and more cost-efficient systems designed for high-volume workloads.
The new models are positioned to support applications where speed, responsiveness and cost efficiency are critical, including coding assistants, real-time multimodal systems and automated subagent workflows.
According to the company, GPT-5.4 mini represents a major upgrade over its predecessor, offering improvements in coding, reasoning, multimodal understanding and tool use, while operating at more than twice the speed. Despite its lower cost, the model achieves performance levels close to GPT-5.4 in several benchmarks, particularly in coding-related tasks.
GPT-5.4 nano, the smaller of the two models, is designed for lightweight tasks where latency and cost take priority. These include classification, data extraction, ranking and basic coding operations.
The release follows the recent launch of GPT-5.4, which introduced enhancements such as mid-response course correction, improved deep web research capabilities and stronger long-context reasoning.
OpenAI said the new models are tailored for modern AI system design, where multiple models operate together. In such setups, GPT-5.4 can handle high-level planning and coordination, while delegating narrower tasks—such as searching codebases, reviewing files and processing documents—to GPT-5.4 mini instances running in parallel.
Within its Codex environment, the company said GPT-5.4 mini consumes about 30 percent of the GPT-5.4 quota, reducing operational costs to roughly one-third while maintaining strong performance.
GPT-5.4 mini is available across OpenAI’s API, Codex and ChatGPT, supporting text and image inputs, tool use, function calling, web and file search, as well as computer-use capabilities. It also features a context window of up to 400,000 tokens.
In ChatGPT, the model is accessible to Free and Go users through the “Thinking” option, and also serves as a fallback for GPT-5.4 Thinking under usage limits. GPT-5.4 nano, meanwhile, is currently available through the API only.
For developers, OpenAI said pricing for GPT-5.4 mini is set at $0.75 per million input tokens and $4.50 per million output tokens, while GPT-5.4 nano is priced at $0.20 per million input tokens and $1.25 per million output tokens.
The launch underscores a broader industry shift toward optimising AI models for scalability and real-world deployment, as companies seek to balance performance with cost and speed in increasingly complex AI-driven applications.
