Claude Opus 5 vs GPT-5.6 Sol

Claude Opus 5 (Anthropic) and GPT-5.6 Sol (OpenAI) compared on price, context window, speed and independent benchmarks. Claude Opus 5 scores higher on the Artificial Analysis Intelligence Index (63.1 vs 60.9), while GPT-5.6 Sol is 1.3× cheaper on a blended basis. Pick Claude Opus 5 for the hardest tasks and GPT-5.6 Sol when cost dominates.

Claude Opus 5GPT-5.6 Sol
ProviderAnthropicOpenAI
Input $/1M$5.00$4.00
Output $/1M$25.0$20.0
Blended $/1M (3:1)$10.0$8.00
Cached input $/1M$0.50$0.40
Context window1M1.1M
Knowledge cutoff2026-052026-02
Licenseproprietaryproprietary
Speed (tok/s)5281
Artificial Analysis Intelligence Index63.160.9
LMArena Elo15051455
GPQA Diamond93.2%94.1%
SWE-bench Verified97%
LiveCodeBench74.6%
MMLU-Pro91.6%
Humanity's Last Exam54.9%49.5%

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