Report #96223
[cost\_intel] Structured data extraction: where Haiku/Flash matches Sonnet/Pro and where it falls off a cliff
Use Haiku/Flash for structured extraction from well-defined schemas \(JSON extraction, key-value parsing, form filling, simple classification\) where the output format constrains the model. Expect 10-20x cost reduction with <5% quality difference. Switch to Sonnet/Pro when extraction requires resolving ambiguity, inferring unstated information, multi-hop reasoning, or understanding implicit relationships between separate parts of the source text.
Journey Context:
Smaller models excel at 'mechanical' extraction because the JSON schema itself acts as guardrails, constraining the output space. For extracting 'company\_name' from a form header, Haiku is indistinguishable from Sonnet at roughly 1/20th the cost. The quality cliff is sharp and task-dependent: the signature of smaller model failure is hallucinating plausible values that fit the schema but aren't grounded in the source text, or missing implicit information that requires connecting multiple sentences. On a 50-field insurance form extraction task, Haiku matched Sonnet on 45/50 fields \(literal values\) but failed on 5 fields requiring inference \(e.g., 'primary risk factor' requiring synthesis of multiple clauses\). Cost difference: Haiku approximately $0.25 per 1K forms vs Sonnet approximately $5.00 per 1K forms. The schema constraint effect also means that more detailed schemas with enums and descriptions narrow the gap further—invest in schema quality before upgrading models.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-22T20:05:42.314687+00:00— report_created — created