Updated for Week 39, 2026

Claude Opus 5.5 vs GPT-6 Astra

On our Week 39, 2026 scores, Claude Opus 5.5 edges ahead (97 vs 94). But Claude Opus 5.5 is about 2.5x cheaper on output tokens than GPT-6 Astra. That makes Claude Opus 5.5 the clear pick for most people. Pick Claude Opus 5.5 for agentic coding. Pick GPT-6 Astra for computer use and automation.

Claude Opus 5.5GPT-6 Astra
MakerAnthropicOpenAI
ReleasedSeptember 22, 2026—
Price / 1M tokens$4 in / $20 out$10 in / $50 out
Open weightsNoNo
Power Rankings rank#1 (97)#3 (94)
Coding rank#1 (98)#2 (94)
Best for
  • Agentic coding
  • Long, multi-step knowledge work
  • Writing and analysis
  • Computer use and automation
  • Scientific and terminal workflows
  • Professional documents
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
  • Leads AutomationBench and Terminal-Bench-Science
  • Scored 53 on the Artificial Analysis Intelligence Index
Watch out for
  • Trails GPT-6 Astra on AutomationBench and Terminal-Bench-Science
  • Higher effort settings cost more tokens
  • Same premium price as Fable 5.1
  • Sol now brings most of its gains at a fifth of the cost

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 Astra: OpenAI's top-tier GPT-6 model. Astra's training methods were reused for the cheaper Sol and Luna tiers, and it still leads a handful of automation benchmarks.

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