Claude Opus 4.8 vs Claude Fable 5

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

Claude Opus 4.8

Anthropic

AI Mastery Index94.6

LMSYS Arena1463

Technical (MMLU-Pro)94.5%

Cost per 1M Tokens$5

Claude Fable 5

Anthropic

AI Mastery Index96.4

LMSYS Arena1494

Technical (MMLU-Pro)95.6%

Cost per 1M Tokens$10

Architect's Verdict

When comparing Claude Opus 4.8 and Claude Fable 5, Claude Fable 5 edges out in overall capabilities according to the AI Mastery Index. However, for cost-sensitive workloads, Claude Opus 4.8 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.