Claude 3.5 Sonnet vs Claude Opus 4.1

Claude 3.5 Sonnet

Anthropic

Claude 3.5 Sonnet, updated by Anthropic in October 2024 (originally released June 2024), is a large language model from the Claude 3.5 family that delivered strong performance in coding, reasoning, and instruction-following at its release. It supports a 200K token context window, 8K maximum output tokens, and native image understanding including screenshot analysis and document comprehension. Claude 3.5 Sonnet targets general-purpose development tasks, document analysis, and applications requiring reliable instruction following with visual input support.

Claude Opus 4.1

Anthropic

Claude Opus 4.1, released by Anthropic in August 2025, is a large language model from the Claude 4 family optimized for demanding reasoning, multi-step coding, and extended analysis tasks. It features a 200K token context window, 32K maximum output tokens, native image understanding, and extended thinking capabilities. Opus 4.1 targets complex problem-solving, multi-turn reasoning workflows, and applications requiring deep analysis with integrated tool use.