Claude Sonnet is the model most B2B teams interact with through Claude Team, Claude Code, and the Anthropic API. Here's what it is, where it fits in the Claude family, and what it's good at.
Claude Sonnet is the mid-tier model in Anthropic's Claude family — Anthropic's daily-driver model balancing capability and cost. As of mid-2026 the current version is Sonnet 4.7, available through Claude Team, Claude Code, and the API. It's the model behind most B2B Claude workflows because it handles 95%+ of business tasks excellently.
Anthropic's Claude family has three tiers, roughly: Haiku (smallest, fastest, cheapest), Sonnet (mid-tier workhorse), and Opus (largest, most capable, slowest, most expensive).
Sonnet is the default for almost every business use case. Strong reasoning, strong writing, strong coding, broad knowledge — at a price point that scales for production usage.
Most teams never need Opus. Cases where Opus is worth the cost:
For everyday business writing, drafting, synthesis: Sonnet.
Sonnet and GPT-5-class models trade leadership across benchmarks. For most business workflows, the practical difference is small; for writing-heavy work, Sonnet usually feels slightly more nuanced.
Opus is more capable on hard reasoning; Sonnet is faster and cheaper. For most business uses Sonnet is the right choice.
Pricing varies by version; check Anthropic's current pricing. Roughly a small fraction of a cent per typical business prompt.
Anthropic ships new versions every few months. Each version is generally a meaningful improvement.
In the API and Claude Code, yes. In Claude.ai and Claude Team UIs, model selection is per-conversation.