Claude Opus
Anthropic's most capable Claude tier — highest reasoning quality at the highest cost and latency.
Definition
Claude Opus is the top of Anthropic's model lineup, used for tasks where reasoning depth matters more than speed or price: complex multi-step debugging, novel architectural decisions, careful code review. It is markedly slower and more expensive per token than Sonnet, so most agents reserve Opus for hard subtasks and run Sonnet by default.
When to use
See also
- Claude Sonnet — Anthropic's mid-tier Claude model family — the default workhorse balancing speed, cost, and reasoning quality.
- Claude Haiku — Anthropic's smallest, fastest, cheapest Claude tier — used for bulk classification, routing, and trivial agent steps.
- LLM — Large Language Model — a transformer-based model trained on internet-scale text to generate and reason.