BreakingFebruary 15, 2026
Claude Sonnet 5 'Fennec' Officially Launches: 80.9% SWE-bench at Half Price
Anthropic confirms Claude Sonnet 5 release with Opus 4.5-level performance at dramatically lower pricing. The 'Fennec' leak proven accurate.
Fennec Becomes Reality
Anthropic officially launched Claude Sonnet 5 on February 15, 2026, confirming weeks of speculation following the "Fennec" leak.
Confirmed Specifications
Model ID: claude-sonnet-5-20260215 Context Window: 500K tokens (2.5x previous) SWE-bench Verified: 80.9% Pricing: $1.50/$7.50 per million tokensPrice Revolution
Sonnet 5 matches Opus 4.5 performance at one-tenth the cost—a game-changer for developers and enterprises alike.