GPT-5.4 mini Rollout

OpenAI is rolling out GPT-5.4 mini across ChatGPT tiers. Free and Go users can access it via the "Thinking" feature in the + menu, while paid users (Plus, Pro, and others) will see it deployed as a rate-limit fallback for GPT-5.4 Thinking during peak usage periods. Enterprise customers retain the option to set Auto routing to default to GPT-5.4 mini if preferred. GPT-5.4 mini will not appear as a selectable model in the model picker, and the older GPT-5 Thinking mini will be retired within 30 days.

GPT-5.3 Instant Improvements

GPT-5.3 Instant has been updated to improve follow-up tone and reduce teaser-style phrasing such as "If you want…", "You'll never believe…", and "I can tell you these three things that…". The broader March 3 update to GPT-5.3 Instant delivered more accurate answers, richer web search results, and reduced unnecessary caveats and overly declarative phrasing that interrupted conversational flow.

GPT-5.4 Thinking Enhancements

GPT-5.4 Thinking now provides an upfront plan of its reasoning, allowing users to adjust course mid-response without additional turns. The model improves deep web research for highly specific queries, maintains context better for longer questions, and features improved context window management for extended thinking. These changes deliver higher-quality answers that arrive faster.

Model Retirements

As of March 11, 2026, GPT-5.1 models are no longer available in ChatGPT, including GPT-5.1 Instant, GPT-5.1 Thinking, and GPT-5.1 Pro. Existing conversations automatically migrate to corresponding current models (GPT-5.3 Instant, GPT-5.4 Thinking, or GPT-5.4 Pro). Earlier, on February 13, 2026, OpenAI retired GPT-4o, GPT-4.1, GPT-4.1 mini, and OpenAI o4-mini from ChatGPT, with no API changes at that time.