Claude 3.5 Sonnet vs GPT-5.6 Sol

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

Claude 3.5 Sonnet

Anthropic

AI Mastery Index88

LMSYS Arena1282

Technical (MMLU-Pro)88.3%

Cost per 1M Tokens$3

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 Claude 3.5 Sonnet 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, Claude 3.5 Sonnet offers a more economical API at $3 per 1M tokens. Your choice should depend heavily on whether you prioritize raw reasoning (MMLU) or scalable deployment economics.