Updated for Week 39, 2026

GPT-6 Sol vs GPT-6 Luna

On our Week 39, 2026 scores, GPT-6 Sol edges ahead (92 vs 82). But GPT-6 Luna is about 20x cheaper on output tokens than GPT-6 Sol. If cost matters more than the last few points of quality, GPT-6 Luna is the smarter buy. Pick GPT-6 Sol for daily work in ChatGPT. Pick GPT-6 Luna for chatbots and customer support.

GPT-6 SolGPT-6 Luna
MakerOpenAIOpenAI
ReleasedSeptember 22, 2026September 22, 2026
Price / 1M tokens$2 in / $10 out$0.1 in / $0.5 out
Open weightsNoNo
Power Rankings rank#4 (92)#11 (82)
Coding rank#4 (90)—
Best Value rank#3 (91)#2 (93)
Best for
  • Daily work in ChatGPT
  • Coding in Codex
  • Balanced cost vs. quality
  • Chatbots and customer support
  • Classification and extraction
  • Anything at scale
Strengths
  • Half the price of GPT-5.6 Sol's promo rates
  • Fewer factual mistakes
  • Available in ChatGPT, Codex, the API and GitHub
  • $0.10 per million input tokens
  • Optimised for fast responses
Watch out for
  • Less reasoning headroom than Astra
  • Brand-new; independent testing still coming in
  • Not built for hard multi-step reasoning

The short version

GPT-6 Sol: OpenAI's everyday workhorse. Sol brings Astra-style improvements to a much cheaper tier, and OpenAI says it makes about half as many mistakes as GPT-5.6 Sol.

GPT-6 Luna: The fast, cheap GPT-6. Luna is built for high-volume jobs where speed and cost matter more than deep reasoning.

Rankings change every week. Check the latest standings or swap in a different model.