Claude Opus vs Claude Sonnet vs Claude Haiku: Which Should You Use?

Anthropic offers Claude in three tiers — Opus, Sonnet, and Haiku — and understanding when to use which one can save you money and get you better results for your specific task.

Claude Haiku is the fastest and most cost-efficient model. It's designed for tasks that don't require deep reasoning — simple question answering, categorization, summarization of short texts, quick content generation. If you're building an application that needs to respond to thousands of requests quickly and cheaply, Haiku is what you want. It's also great for real-time use cases where latency matters.

Claude Sonnet hits the sweet spot for most professional tasks. It's significantly more capable than Haiku for complex writing, analysis, and coding, while still being fast and reasonably priced. Most everyday professional use cases — drafting emails, summarizing documents, writing code, doing research — are well served by Sonnet. It's the model that most Claude users end up using for the majority of their work.

Claude Opus is the flagship model, designed for the hardest tasks. If you're doing serious research synthesis, complex multi-step reasoning, detailed code review, or nuanced analysis where getting things right really matters, Opus is worth the additional cost and slightly slower response time. It's also the model that handles very long documents most effectively.

For developers building with the API, a common pattern is to use Haiku for high-volume lightweight tasks, Sonnet for standard workloads, and Opus only when a task genuinely requires the extra capability. This keeps costs manageable while still having access to the best performance when you need it.

For individual users on Claude.ai, the plan you're on determines which models you can access. Free users get access to lighter models; Pro subscribers get access to the full range including Opus.