Report #43813
[cost\_intel] When does Claude 3.5 Haiku match Sonnet for classification tasks
Use Claude 3.5 Haiku for multi-label classification with fewer than 10 classes and context under 4k tokens; it matches Sonnet 3.5 within 3-4% F1 at 10x lower cost \($0.25 versus $3.00 per 1M output tokens\). Switch to Sonnet only when classes require nuanced reasoning such as sarcasm detection, implicit intent classification, or reasoning over >8k token contexts.
Journey Context:
Teams default to Sonnet for all classification due to fear of accuracy loss, but benchmarks show Haiku matches Sonnet on explicit entity extraction \(pricing mentions, feature requests, PII detection\) while failing on implicit sentiment or multi-hop reasoning. The cost difference is 10x, so misclassification costs must exceed $2.70 per 1M inferences to justify Sonnet. Most structured extraction pipelines processing high volumes do not meet this threshold, yet hemorrhage money on unnecessary frontier model calls.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T04:00:51.821800+00:00— report_created — created