GPT 5.5

proprietary

GPT-5.5 is a flagship model for the most complex professional work. Learn more in our GPT-5.5 model guidance. Reasoning.effort supports: none, low, medium (default), high and xhigh.

Intelligence
Reasoning
Speed
Context
1.1M
Max output
128K
Input price
$5/1M tokens
Output price
$30/1M tokens

Capabilities

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

Details

Model IDgpt-5.5
Provider OpenCode Zen
Creator OpenAI
Familygpt-5.5
Licenseproprietary
Statusactive
Typechat
Input modalitiestext
Output modalitiestext
Open weightNo
Parameters—
Architecture—
Context window1.1M tokens
Max input—
Max output128K tokens
Reasoning tokensYes
Knowledge cutoff
Release date
Sourceofficial

Pricing

Context lengthPer 1M tokens
InputOutputCached ReadCached Write
≤ 272K tokens$5$30$0.5—
> 272K tokens$10$45$1—

Family Comparison: gpt-5.5

ModelContextMax outPricing
GPT 5.51.1M128K$5$30
GPT 5.5 Pro1.1M128K$30$180

API

GET/v1/models/opencode/gpt-5.5