Choosing between Claude's model tiers isn't about picking "the best" — it's about matching capability to context. Each tier represents a different point on the capability-speed-cost curve.
The Model Family at a Glance
Haiku is the speed tier. It processes simple tasks in milliseconds, handles classification, extraction, and short-form generation with remarkable efficiency. When you need answers fast and the task is well-defined, Haiku is almost always the right choice.
Sonnet is the versatile middle ground. It handles most knowledge work — drafting, analysis, coding, conversation — with strong accuracy and reasonable latency. For the majority of real-world applications, Sonnet offers the best overall value.
Opus is the depth tier. When a task requires extended reasoning, multi-step planning, or expert-level analysis, Opus brings capabilities that the other tiers can't match. It's slower and more expensive, but the quality ceiling is meaningfully higher.
A Decision Framework
Ask three questions:
1. How complex is the reasoning? Simple extraction → Haiku. Standard knowledge work → Sonnet. Multi-step analysis → Opus.
2. What's the cost of being wrong? Low stakes → Haiku or Sonnet. High stakes → Sonnet or Opus.
3. How much does latency matter? Real-time interaction → Haiku. Moderate patience → Sonnet. Quality over speed → Opus.
Common Patterns
Many production systems use multiple tiers: Haiku for routing and classification, Sonnet for the main workload, and Opus for quality-critical steps like final review or complex edge cases.
This tiered approach often outperforms using a single model for everything — you get better results *and* lower costs.