Updated for Week 39, 2026

Claude Opus 5.5 vs GPT-6 Sol

On our Week 39, 2026 scores, Claude Opus 5.5 edges ahead (97 vs 92). But GPT-6 Sol is about 2x cheaper on output tokens than Claude Opus 5.5. If cost matters more than the last few points of quality, GPT-6 Sol is the smarter buy. Pick Claude Opus 5.5 for agentic coding. Pick GPT-6 Sol for daily work in ChatGPT.

Claude Opus 5.5GPT-6 Sol
MakerAnthropicOpenAI
ReleasedSeptember 22, 2026September 22, 2026
Price / 1M tokens$4 in / $20 out$2 in / $10 out
Open weightsNoNo
Power Rankings rank#1 (97)#4 (92)
Coding rank#1 (98)#4 (90)
Best Value rank—#3 (91)
Best for
  • Agentic coding
  • Long, multi-step knowledge work
  • Writing and analysis
  • Daily work in ChatGPT
  • Coding in Codex
  • Balanced cost vs. quality
Strengths
  • Led six of the nine benchmarks Anthropic published at launch
  • 66.4% on Terminal-Bench 4.0 at extra-high effort
  • Much cheaper than the Fable/Mythos tier
  • Half the price of GPT-5.6 Sol's promo rates
  • Fewer factual mistakes
  • Available in ChatGPT, Codex, the API and GitHub
Watch out for
  • Trails GPT-6 Astra on AutomationBench and Terminal-Bench-Science
  • Higher effort settings cost more tokens
  • Less reasoning headroom than Astra
  • Brand-new; independent testing still coming in

The short version

Claude Opus 5.5: Anthropic's new default flagship. Opus 5.5 replaced Opus 5, costs 20% less, and at launch took the top spot on the independent Artificial Analysis Intelligence Index.

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.

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