Anthropic's balanced workhorse — top coding and reasoning at mid cost.
Claude Sonnet 4.5 is the 2026 mid-tier Anthropic model that most teams standardize on: elite coding, strong agentic reliability, and a calm, precise writing voice. It sits between the lighter Haiku and the heavier Opus.
Who it's for: Coding teams and creators who want production-grade results without a heavy toolchain.
Top-tier repo-scale edits and test generation.
Strong on math, analysis, and planning.
Handles big specs and diffs natively.
Stable function calling for agents.
Claude Sonnet 4.5 is a serious 2026 contender in the coding space. If you already live in this category's ecosystem, it's worth the switch; for newcomers it's one of the fastest ways to get production results.