Report #49255
[cost\_intel] When does Claude 3 Haiku match Sonnet for text classification accuracy
Use Haiku for binary/multi-class classification with <10 classes and clear label definitions; expect 3-5% accuracy drop vs Sonnet but 8x cost reduction \($0.25 vs $3 per 1M tokens input\). Switch to Sonnet when classes >20, labels are semantically close \(e.g., frustrated vs disappointed\), or context window exceeds 8k \(Haiku's recall degrades faster than Sonnet's\).
Journey Context:
Common mistake is assuming smaller models fail at all classification. For well-defined taxonomies with distinct decision boundaries, Haiku achieves >95% of Sonnet's F1. The cliff happens at class granularity—Haiku confuses adjacent sentiment labels that Sonnet distinguishes. Cost math: At 1M classifications/month, Haiku=$250 vs Sonnet=$3000. Quality degradation signature: Watch for soft confusion—Haiku returns low confidence for valid examples where Sonnet is certain.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T13:09:23.598420+00:00— report_created — created