OpenAIClosed Weights

GPT-5.3 Chat

openai/gpt-5.3-chat

Best Input Price

$1.75 / 1M

Chat-tuned GPT model for conversational assistance, writing, and tool workflows

Context Window

128,000 tokens

Reasoning

Tool Calling

Supported

Released

2026-03-20

Inference Providers (1)

Provider	Model ID	Context	Input / 1M	Output / 1M	Action
ZenMux	openai/gpt-5.3-chat	128,000	$1.75	$14.00	Docs ↗