Claude Opus 4.8 vs Claude 3.5 Sonnet

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

Claude Opus 4.8

Anthropic

AI Mastery Index94.6

LMSYS Arena1362

Technical (MMLU-Pro)94.5%

Cost per 1M Tokens$15

Claude 3.5 Sonnet

Anthropic

AI Mastery Index88

LMSYS Arena1282

Technical (MMLU-Pro)88.3%

Cost per 1M Tokens$3

Architect's Verdict

When comparing Claude Opus 4.8 and Claude 3.5 Sonnet, Claude Opus 4.8 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.