GPT-6.1 Sol vs Claude Opus 5.5

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

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.

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.

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