GPT-6 Sol and Luna cut GPT-5.6 prices in half. Here's what independent tests show, where each model fits, and how they compare with Opus 5.5 and Astra.
Key takeaways
- OpenAI released GPT-6 Sol and GPT-6 Luna on September 22, 2026, at half the list price of GPT-5.6 Sol and Luna.
- GPT-6 Sol costs $2 input and $10 output per million tokens. GPT-6 Luna costs $0.10 and $0.50.
- On independent tests, Sol costs about 47% less per task than GPT-5.6 Sol and runs about 55% faster, but scores just 1 point higher.
- Luna scores the same as GPT-5.6 Luna for less than half the cost per task, at about 154 tokens per second.
- Both have weak spots. Sol slipped on one knowledge-work test, and Luna scores near zero on a factual-recall test that penalizes wrong answers.
📖 Read the full guide on Van Data Team → GPT-6 Sol and Luna: Half the Price, and Where Each One Fits
