gpt-5.1-chat Preview

Historical specifications. - Reasoning - Chat Completions API. - Responses API . - Structured outputs - Functions, tools, and parallel tool calling.

Context
128K
Max output
16K

Capabilities

Reasoning & Interaction
Reasoning
Tool Calling
Output Control
Structured Output
JSON Mode
Infrastructure
Streaming

Details

Model IDgpt-5.1-chat
Provider Azure AI Foundry
Creator OpenAI
Familygpt-5.1
License—
Status—
Typechat
Input modalitiestext
Output modalitiestext
Open weight—
Parameters—
Architecture—
Context window128K tokens
Max input—
Max output16K tokens
Reasoning tokens—
Knowledge cutoff
Release date—
Sourceofficial

Tools

Function Callingfunction_calling
Call external functions and APIs

Family Comparison: gpt-5.1

ModelContextMax out
gpt-5.1-chat Preview128K16K
gpt-5.1-codex-max400K128K
gpt-5.1-codex-mini400K128K
gpt-5.1-codex400K128K
GPT-5.1 series400K128K

API

GET/v1/models/azure/gpt-5.1-chat