Updates to ChatGPT: You can now choose between “Auto”, “Fast”, and “Thinking” for GPT-5. Most users will want Auto, but the additional control will be useful for some people. Rate limits are now 3,000 messages/week with GPT-5 Thinking, and then extra capacity on GPT-5 Thinking…

But the launch of GPT-5 means the demise of older OpenAI models, including GPT-4o, o3, o4-mini, GPT-4.1, and GPT-4.5. Many users have taken to social media to complain about how that's disrupted their workflows,

ChatGPT’s GPT-5 rollout brings new modes and restores legacy models, reflecting OpenAI’s efforts to align AI performance and personality with user preferences.