Haiku vs Sonnet: Which AI Model Should Your Team Use?

The Cost Difference Is 76%. Here's When It Matters.

Claude Haiku costs $0.80 per million input tokens. Claude Sonnet costs $3.00. For output: $4.00 vs $15.00. At moderate volume, the difference is significant.

When to Use Haiku

Structured tasks with clear input/output: summarization, classification, extraction, drafting from templates, code review against a checklist. If you can describe the task precisely, Haiku handles it.

When to Use Sonnet

Complex reasoning, ambiguous problems, nuanced writing, tasks where the quality difference is visible to end users. Synthesis over pattern-matching.

Real Numbers

500 calls/day, 400 input tokens, 250 output tokens: Sonnet costs ~$72/month. Haiku costs ~$13/month. Savings: $59/month.

Try the Calculator

Enter your actual usage at http://143.198.136.81:8802/tools/roi-calc — it calculates your exact monthly savings and how quickly a PromptLab subscription ($29/mo) pays for itself.

Free Model Comparison Tool

Run any prompt through both models side-by-side and see the real cost difference: http://143.198.136.81:8802/promptlab/health (POST /promptlab/compare with your prompt)