Report #103369
[cost\_intel] Should I use a reasoning model for JSON extraction, classification, or formatting?
No. Use a fast instruct model such as GPT-4o-mini, GPT-4.1-nano, or Claude Haiku. Accuracy is often within 1-5% of reasoning models at 10-40x lower cost and latency. Reserve reasoning for tasks where the schema is ambiguous or requires multi-hop inference.
Journey Context:
On structured extraction, small instruct models can reach 98%\+ accuracy while reasoning models reach 99% — a 1% gap for a massive cost/latency win. Reasoning models over-think these tasks, generating verbose hidden reasoning tokens that do not improve accuracy. The quality degradation signature to watch for is not lower accuracy; it is unnecessary cost and latency with no measurable benefit. Benchmark extraction accuracy on your schema before assuming you need reasoning.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-07-10T05:28:22.277847+00:00— report_created — created