GPT-5.4 Thinking rolls out to ChatGPT with mid-response interrupts

GPT-5.4 Thinking is rolling out to ChatGPT, and users can now interrupt it before it produces the final answer. Users can steer the response while it is still working rather than sending multiple follow-up turns. The update also improves deep web research and long-context reasoning, which the post says helps specific questions arrive faster and stay focused.