Today, we’re releasingGPT-5.3 Instant Miniin ChatGPT. It replaces GPT-5 Instant Mini as the fallback model users reach after hitting their rate limits for GPT-5.3 Instant. Because it serves as a fallback, it won’t appear in the model picker.Compared with GPT-5 Instant Mini, GPT-5.3 Instant Mini feels more natural in conversation, with stronger writing and contextual awareness throughout chats. It outperforms GPT-5 Instant Mini across a range of use cases.