gpt-5.1-plus

GPT-5.1-Plus is an iterative version based on GPT-5, featuring "fast response + a more natural conversation experience." It delivers comprehensive upgrades in response speed, instruction adherence, and conversational tone, with the official claim that it feels "warmer and smarter," making it especially suited for high-frequency interaction scenarios such as daily chats, summarization, Q&A, lightweight reasoning, and customer service bots. Compared to the previous GPT-5 version, it can execute user instructions more accurately (e.g., strictly controlling word count) and offers a tone that closely mirrors human speech.