Claude Haiku vs Sonnet: 4-Dimension Buying Guide

1. How Big Is the Price Gap?

Anthropic Official: Sonnet 4.5 = $3/M input, $15/M output; Haiku 4 = $0.80/M input, $4/M output. The gap is 3-4x. See full prices on the pricing page.

2. 4-Dimension Comparison

1. Capability — Sonnet is 30-50% stronger than Haiku on reasoning / long-form / code; Haiku is ~95% on par on classification / extraction / translation
2. Speed — Haiku is 2-3x faster than Sonnet (ideal for real-time chat)
3. Cost — Haiku is 1/3-1/4 the price of Sonnet (ideal for large batches)
4. Context — Sonnet 200k tokens, Haiku 200k tokens (tied)

3. How to Choose for 5 Task Types?

• Classification / extraction / translation — Haiku (sufficient + 4x cheaper)
• Real-time chat / customer service — Haiku (fast + cheap)
• Complex reasoning / long-form analysis — Sonnet (required)
• Code generation / debugging — Sonnet (required)
• Large-batch data processing — Haiku (cost-first)

4. Decision Checklist

1. Current public price on Anthropic Official = cost floor

2. Haiku cross-provider price = lowest relay

3. Sonnet cross-provider price = use when upgrading

4. Run a test with Claude Detection = verify capability