Anthropic publishes its own guide to choosing among the four Claude models. Spec Sheet 01 restates it for the operator's desk. The quotes are Anthropic's. The desk jobs and the human lock are ours, and the header on each page says which voice you're reading.
Start on Sonnet for most work. Drop to Haiku for simple, repetitive tasks, and move to Opus for complex work you'll question and redirect as you go. Move up when a model struggles, and move down when a cheaper one holds up. Then check your own desk for the habit of sending every task to the same model: the inbox sort can go to Haiku, the budget scenarios to Opus, and the grant report to Fable.
Source: Anthropic, “Choosing the right Claude model: Haiku, Sonnet, Opus, or Fable.” Claude Academy. academy.claude.com/tutorials/choosing-the-right-claude-model
First posted on the Ops Bureau Company Page Sep 29, 2026. Quotes checked against the source Sep 28 and again Oct 7, 2026: unchanged. Model lineups change. If this guide changes, this sheet gets marked retired here.
Ops Bureau is independent and not affiliated with Anthropic.