Model
GPT-5.6 (Sol / Terra / Luna)
by OpenAI
Family
GPT-5
Context window
1,000,000 tokens
Open weights
No
Release date
2026-07-09
Benchmark notes
Current frontier generation as of July 2026. Sol tier is OpenAI's highest-capability model for complex reasoning, coding, biology, and cybersecurity tasks. GPT-5.6 Sol cyber safeguards block approximately ten times more potentially harmful activity than predecessor models. Sol/Terra served with activation classifiers for sensitive-domain safety. Three named tiers: Sol (maximum capability), Terra (balanced intelligence/cost), Luna (cost-optimized high-volume).