Claude Opus 5.5 vs GPT-6.1 Sol

A direct, empirical evaluation of Claude Opus 5.5 (Anthropic) against GPT-6.1 Sol (OpenAI).

Claude Opus 5.5

Developed by Anthropic · Proprietary Frontier Reasoner parameters

Autonomous enterprise codebase migrations, GitHub Copilot multi-file edits, SWE-bench Pro issue resolution (89.9%), and CodeRabbit automated reviews.

GPT-6.1 Sol

Developed by OpenAI · Proprietary Frontier Workhorse Engine parameters

Near-Astra reasoning at 1/5th price ($1.25/$5.00), SWE-bench Verified 74.8%, OSWorld 2.0 desktop agent automation, and sub-80ms Ultrafast Mode.

Metric Claude Opus 5.5 GPT-6.1 Sol
SWE-bench Verified 89.9% 74.8%
MMLU-Pro 92.4% 92.4%
MATH-500 97.2% 96.2%
Context Window 500,000 tokens 1,000,000 tokens
Input Pricing (per 1M) $4.00 $1.25
Output Pricing (per 1M) $20.00 $5.00