Back to AnthropicModel Familyclaude-sonnet-4Developed by Anthropic. Explore the 2 variants available in this generation.Claude Sonnet 4.6AnthropicAnthropicAPIFeb 2026Lineageclaude-sonnet-4 (Sonnet)|claude-sonnet-5 (Sonnet)Claude Sonnet 4.5AnthropicAnthropicAPISep 2025LineageClaude 4 (Sonnet)|claude-sonnet-4 (Sonnet)