What is the context window of GPT-5.1 Chat?

GPT-5.1 Chat has a context window of 128K tokens.

When was GPT-5.1 Chat released?

GPT-5.1 Chat was released on 2025-12-01.

Name: GPT-5.1 Chat
Author: OpenAI

gpt-5.1-chat

ProprietaryMultimodal

GPT-5.1 Chat is the fast, lightweight conversational member of the GPT-5.1 family, optimized for low-latency chat at 128K context.

GPT-5.1 Chat has a 128K-token context window.

VisionMultimodalReasoningFunction CallingTool UseStructured OutputsCode Execution

Released2025-12-01

Context128K

ArchitectureDecoder Only

Specializationgeneral

LicenseProprietary

Trainingpretrained

Cutting-edge research and development.

San Francisco, California, United States

Founded 2015