This technical report serves as an addendum to the Claude 3 Model Card, detailing the enhancements and evaluations of the Claude 3.5 Sonnet model. The document outlines the model's improved capabilities over its predecessor, Claude 3 Opus, highlighting its faster operation and lower cost. It presents comprehensive evaluations across various benchmarks, including reasoning, coding, and visual processing, where Claude 3.5 Sonnet demonstrates superior performance. The report includes specific results from safety testing, emphasizing the model's advancements in handling coding tasks and visual comprehension. Additionally, it discusses the model's ability to differentiate between harmful and benign requests, showcasing its improved refusal rates. The report also addresses the safety evaluations conducted to assess risks associated with the model, including its classification as an AI Safety Level 2 model. Overall, the document provides a detailed account of the model's capabilities and safety assessments, contributing to the understanding of its operational effectiveness.