OpenAI: GPT-5.1 Chat

OpenAIenterpriseModerated
openai/gpt-5.1-chat

Description

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...

Specifications

Context Window

128,000

tokens

Max Completion Tokens

16,384

tokens

Input Modalities

fileimagetext

Output Modalities

text

Supported Parameters

max_completion_tokensmax_tokensresponse_formatseedstructured_outputstool_choicetools

Pricing

Price TypeRateUnit
Input (Prompt)$0.000001per 1M tokens
Output (Completion)$0.000010per 1M tokens
Web Search$0.010000per query
Cache Read$0.000000per 1M tokens

Tier Availability

Free

Not Available

Pro

Not Available

Enterprise

✓ Available