Back to all models
openai
OpenAI: GPT-5.1 Chat
GPT-5.1 Chat (AKA Instant is the fast, lightweight member of the 5.1 family, optimized for low-latency chat while retaining strong general intelligence. It uses adaptive reasoning to selectively “think” on harder queries, improving accuracy on math, coding, and multi-step tasks without slowing down typical conversations. The model is warmer and more conversational by default, with better instruction following and more stable short-form reasoning. GPT-5.1 Chat is designed for high-throughput, interactive workloads where responsiveness and consistency matter more than deep deliberation.
openai/gpt-5.1-chat
Context Size
128K
Input Price
7,687.5 Ks/M
Output Price
61,500 Ks/M
Architecture
File
Image
Text
Supported Parameters
max_tokensresponse_formatseedstructured_outputstool_choicetools
Details
TokenizerGPT
Max Completion16,384 tokens
Provider Context128K tokens
ModeratedYes