OpenAI: GPT-5.1 Chat

GPT

Multimodal

Paid

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 harder queries, improving accuracy on math, coding, and multi-step tasks without slowing down typical conversations. The model is warmer and more conversational by default, with better instruction following and more stable short-form reasoning. GPT-5.1 Chat is designed for high-throughput, interactive workloads where responsiveness and consistency matter more than deep deliberation.

Parameters

Context Window

128,000

tokens

Input Price

$1.25

per 1M tokens

Output Price

$10

per 1M tokens

Capabilities

Model capabilities and supported modalities

Performance

Reasoning

Excellent reasoning capabilities with strong logical analysis

Math

Strong mathematical capabilities, handles complex calculations well

Coding

Knowledge

Modalities

Input Modalities

file,image,text

Output Modalities

text

LLM Price Calculator

Calculate the cost of using this model

Input Tokens (0.00000125/token)$0.001875

Output Tokens (0.00001000/token)$0.030000

Common Scenarios:

Input Cost:$0.001875

Output Cost:$0.030000

Total Cost:$0.031875

Estimated usage: 4,500 tokens

Monthly Cost Estimator

Based on different usage levels

Light Usage

$0.1125

~10 requests

Moderate Usage

$1.1250

~100 requests

Heavy Usage

$11.2500

~1000 requests

Enterprise

$112.5000

~10,000 requests

Note: Estimates based on current token count settings per request.

Last Updated: 1970/01/21