GPT-4o-mini vs Gemini 3.1 Ultra

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

GPT-4o-mini

OpenAI

AI Mastery Index81

LMSYS Arena1270

Technical (MMLU-Pro)82%

Cost per 1M Tokens$0.15

Gemini 3.1 Ultra

Google

AI Mastery Index92.5

LMSYS Arena1320

Technical (MMLU-Pro)92.5%

Cost per 1M Tokens$20

Architect's Verdict

When comparing GPT-4o-mini and Gemini 3.1 Ultra, Gemini 3.1 Ultra edges out in overall capabilities according to the AI Mastery Index. However, for cost-sensitive workloads, GPT-4o-mini offers a more economical API at $0.15 per 1M tokens. Your choice should depend heavily on whether you prioritize raw reasoning (MMLU) or scalable deployment economics.