I tested the new ChatGPT-5.4 mini and nano models (www.techradar.com)

OpenAI has launched the GPT-5.4 mini and nano models, providing Free and Go users access to advanced capabilities previously reserved for Plus or Pro subscribers. These new models are integrated through the “Thinking” tool in the ChatGPT interface, allowing users to benefit from enhanced reasoning skills without directly selecting the models themselves. Early tests have shown that the “Thinking” versions significantly improve the depth and insight of responses, particularly for complex queries requiring nuanced planning and reasoning. This development is noteworthy for the AI/ML community as it democratizes access to more sophisticated generative AI capabilities, enabling a broader audience to engage with advanced features. Users reported that the mini and nano models produced detailed and thoughtful answers, almost indistinguishable from the full version in terms of content quality but with a notable increase in response speed. This accessibility could shift how various users interact with AI, potentially leading to increased adoption and application of AI in everyday tasks, thereby expanding the scope of tasks AI can assist with efficiently.