GPT-5.6 Luna
The fastest, most cost-efficient GPT-5.6 model — strong everyday capability at OpenAI's lowest price for summarization, drafting, and routine automation
GPT-5.6 Luna
OpenAI • June 2026
Training Data
Not disclosed
GPT-5.6 Luna
June 2026
Parameters
Not disclosed
Training Method
Token-Efficient Unified Architecture
Context Window
1,500,000 tokens
Knowledge Cutoff
Not disclosed
Key Features
1.5M Token Context • Lowest Cost • Fastest Latency • Everyday Automation
Capabilities
Speed: Maximum
Cost-Efficiency: Maximum
Coding: Strong (84.3% Terminal-Bench)
What's New in This Version
OpenAI's lowest-cost model ($1/$6 per 1M tokens) yet scores 84.3% on Terminal-Bench 2.1, tuned for fast, high-volume everyday work; generally available since July 9, 2026
The fastest, most cost-efficient GPT-5.6 model — strong everyday capability at OpenAI's lowest price for summarization, drafting, and routine automation
What's New in This Version
OpenAI's lowest-cost model ($1/$6 per 1M tokens) yet scores 84.3% on Terminal-Bench 2.1, tuned for fast, high-volume everyday work; generally available since July 9, 2026
Technical Specifications
Key Features
Capabilities
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