Claude 3.5 Sonnet

Claude 3.5 Sonnet is a mid-tier model in Anthropic's Claude 3.5 series, positioned between the lighter Haiku and the top-end Opus. Per a 2024 BlueRun Ventures share, it was designed to balance processing speed and computational efficiency for enterprise workloads, with a 200K context window and pricing at $3 per million input tokens and $15 per million output tokens . Anthropic described it as particularly suited for data retrieval, sales automation, code generation, and text extraction from images .

By mid-2026, the model had become a reference point for how Anthropic's coding focus paid off. As one investor told 峰瑞资本, Claude 3.5's release marked a noticeable jump in AI coding tool quality, helping kick off a feedback loop where better tools drew more users, whose data in turn improved the model . The same investor noted that users found Claude "严谨、聪明" (rigorous, smart) in part because coding demands the kind of logic and chain-of-thought reasoning that transfers to broader tasks .

In the broader Claude family, 3.5 Sonnet also stood out for Anthropic's safety framing: the company, founded by former OpenAI staff who split over AI safety concerns, trained Claude to follow a "constitution" of principles and reduced its rate of refusing harmless queries compared to earlier versions .