Anthropic · Claude · Fable · Mythos

Claude Sonnet 5

Released 30 Jun 2026 · 21 days after Claude Fable 5

notable release

Near-Opus intelligence at Sonnet cost.

Intelligence

—

no index score yet

Price

$4.00

per 1M tokens, 3:1 in/out · $2 in / $10 out

Speed

—

not measured

Weights

Closed

US lab

Anthropic’s best score over time