GPT-5.1

GPT-5.1 is a large language model within OpenAI's GPT series, released on November 12, 2025.^[1]

GPT-5.1
Developer	OpenAI
Initial release	November 12, 2025; 4 days ago (2025-11-12)
Included with	ChatGPT Microsoft Copilot
Predecessor	GPT-5
Type	Multimodal Large language model Generative pre-trained transformer Foundation model
License	Proprietary
Website	openai.com/index/gpt-5-1/

The model offers 8 personality options.^[2][3] Improvements over its predecessor GPT-5 include less hallucinations and better adherance to prompts.^[3] According to OpenAI, it is faster and has a "warmer personality" by default compared to GPT-5.^[1][4]

The model consists of two modes: GPT-5.1 Instant and GPT-5.1 Thinking, the latter being a reasoning model designed for more complex tasks.^[5]