gpt-5.3-chat

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

Context
128K
Max output
16K

Capabilities

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

Details

Provider Azure AI Foundry
Creator OpenAI
Familygpt-5.3
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-5.3

ModelContextMax out
gpt-5.3-chat128K16K
gpt-5.3-codex400K128K
GPT-5.3 series——

API

GET/v1/models/azure/gpt-5.3-chat

gpt-5.3-chat

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

Changes · 4 entries
gpt-5.3-chatupdateca7a400Nov 2, 2026, 03:02 AM
capabilitiestool callyesstructured outputyesjson modeyes
descriptionHistorical specifications. - Chat Completions API. - Resp...
knowledge_cutoff2025-08
context_window128000
max_output_tokens16384
tagline- Chat Completions API.
tools["function_calling"]
gpt-5.3-chatupdate17bcfbfSep 11, 2026, 06:36 AM
description- Chat Completions API. - Responses API . - Structured ou...→Historical specifications. - Chat Completions API. - Resp...
gpt-5.3-chatupdate73d11c6May 18, 2026, 03:39 AM
description- Chat Completions API. - Responses API . - Structured ou...
knowledge_cutoff2025-08
context_window128000
max_output_tokens16384
tagline- Chat Completions API.
tools["function_calling"]
gpt-5.3-chatcreate6231fb5Apr 22, 2026, 02:50 AM