Gemini 3.1 Ultra vs GPT-5.6 Sol

Head-to-head technical comparison of intelligence, capabilities, and API pricing.

Gemini 3.1 Ultra

Google

AI Mastery Index92.5

LMSYS Arena1480

Technical (MMLU-Pro)92.5%

Cost per 1M Tokens$20

GPT-5.6 Sol

OpenAI

AI Mastery Index95.7

LMSYS Arena1485

Technical (MMLU-Pro)95.1%

Cost per 1M Tokens$5

Architect's Verdict

When comparing Gemini 3.1 Ultra and GPT-5.6 Sol, GPT-5.6 Sol edges out in overall capabilities according to the AI Mastery Index. However, for cost-sensitive workloads, GPT-5.6 Sol offers a more economical API at $5 per 1M tokens. Your choice should depend heavily on whether you prioritize raw reasoning (MMLU) or scalable deployment economics.