ChatGPT — March 18, 2026

Changed

• GPT-5.4 mini in ChatGPT
• We’re rolling out GPT-5.4 mini in ChatGPT. GPT-5.4 mini is available to Free and Go users via the “Thinking” feature in the + menu. For all other users, GPT-5.4 mini is available as a rate limit fallback for GPT-5.4 Thinking. For Plus, Pro, and other paid users, GPT-5.4 mini will be used as a fallback for GPT-5.4 Thinking when rate limits are reached, helping with continued access to reasoning capabilities during high usage. Enterprise customers will retain the option to default Auto routing to GPT-5.4 mini, if preferred. GPT-5.4 mini will not appear as a selectable model in the model picker. Learn more in our blog post.