GPT-6 Luna

Anthropic released Claude Opus 5.5 at $4/$20 per million input/output tokens, undercutting Opus 5's $5/$25 pricing while claiming better agentic coding scores. OpenAI countered with GPT-6 Sol ($2/$10) and GPT-6 Luna ($0.10/$0.50), both up to 50% cheaper than GPT-5.6's promotional rates.

OpenAI has released GPT-6 Luna, the fast and cost-efficient entry in its new GPT-6 model family, featuring a 1.1M token context window and pricing starting at $0.10 per 1M input tokens. The model is positioned below GPT-6 Sol and GPT-6 Astra in OpenAI's tiered lineup.

OpenAI has released GPT-6 Sol and Luna, updated versions of its mid-tier and lightweight models, priced at half the cost of their GPT-5.6 predecessors. The company claims GPT-6 Sol makes roughly half as many factual errors as its predecessor, reaching what it calls 'Astra-level reliability' at lower cost.