OpenAI has launched GPT-5.3 Instant, the latest iteration of its AI model, now set as the default for ChatGPT. This update aims to enhance user interactions by reducing unnecessary refusals and improving the quality of responses, particularly in high-risk fields like medicine, law, and finance. Notably, the hallucination rate has been cut by 26.8% when the model is connected to the internet and by 19.7% when it relies solely on internal data, compared to GPT-5.2 Instant. The new model also addresses issues with tone, reducing inappropriate assumptions and unnecessary statements. GPT-5.3 Instant is available to all ChatGPT users and through the API as gpt-5.3-chat-latest. GPT-5.2 Instant will remain accessible to paying users until its retirement on June 3.