Claude 3.7 Sonnet vs Claude Opus 4.6

Claude 3.7 Sonnet

Anthropic

Claude Sonnet 3.7, released by Anthropic in February 2025, is a large language model from the Claude 3 family featuring hybrid reasoning with configurable extended thinking. It supports a 200K token context window, 64K maximum output tokens (128K in beta), and native image understanding. Sonnet 3.7 targets complex coding, mathematics, and scientific reasoning tasks where extended chain-of-thought processing provides meaningful improvements in output quality.

Claude Opus 4.6

Anthropic

Claude Opus 4.6, released by Anthropic in February 2026, is a large language model from the Claude 4 family designed for complex agent orchestration, extended reasoning, and long-form code generation. It features a 200K token context window (extendable to 1M tokens in beta), 128K maximum output tokens, native image understanding, and extended thinking with both standard and adaptive effort modes. Opus 4.6 targets multi-step agentic workflows, parallel tool use, and applications requiring sustained reasoning over large contexts.