Claude 3.5 Haiku vs Sonnet vs Opus: which one should you actually use?

Source: Dev.to

Overview

Anthropic currently offers five Claude models. Selecting the appropriate model can significantly affect both cost and output quality.

Model Summaries

Haiku

• Purpose: High‑volume tasks
• Strengths: Fastest and cheapest option by a wide margin
• Ideal Use Cases: Classification, routing, quick summarisation, preprocessing pipelines before passing data to a larger model
• Limitations: Struggles with nuanced reasoning, complex code, or ambiguous problems; may hallucinate confidently

Sonnet

• Purpose: General‑purpose default
• Strengths: Strong reasoning, solid code generation, sensible context handling; excellent price‑to‑quality ratio
• Ideal Use Cases: Most applications that don’t require the highest tier of reasoning

Opus

• Purpose: Heavy‑duty reasoning
• Strengths: Handles multi‑step analysis, research synthesis, and complex code that must be correct on the first try
• Limitations: Slow and expensive; often over‑used
• Ideal Use Cases: Tasks that would normally need a senior engineer’s review

Choosing the Right Model

• Start with Haiku for any high‑throughput, low‑complexity workload.
• Default to Sonnet for most product features and general tasks.
• Reserve Opus for genuinely hard reasoning tasks where accuracy outweighs cost.

Comparison Tool

A side‑by‑side comparison page includes pricing, context limits, speed, and a cost calculator to estimate your monthly bill:

Claude Model Comparison

Use this tool to verify the best model for your specific use case before committing.