OpenAI has introduced the GPT 5.4 mini and nano models, making advanced AI capabilities accessible to free users of the ChatGPT platform. The GPT 5.4 mini operates more than twice as fast as its predecessor and closely matches the performance of the larger GPT 5.4 model in key evaluations. These models are designed for environments where latency is critical, excelling in coding, reasoning, multimodal understanding, and tool utilization. The GPT 5.4 mini is available in ChatGPT’s free and Go tiers, as well as in OpenAI’s API and Codex, while the nano variant is accessible exclusively through the API, both at lower costs than the original GPT 5.4 model.