When to reach for a fast model, when it's worth the wait for Opus-class reasoning, and how to compare them live in a session instead of guessing.
The instinct is to always reach for the βbestβ model. In practice, the right question is what the task actually needs β speed, cost, and reasoning depth trade off against each other, and most work doesn't need the most expensive option.
| If the task is... | Reach for... |
|---|---|
| A quick factual question, formatting, simple edits | A fast, lightweight model |
| Drafting routine content, summarizing | A mid-tier model |
| Multi-step reasoning, high-stakes decisions, nuanced writing | A top-tier (Opus-class) model |
| You genuinely don't know which will do better | Compare models side by side (below) |
For anything where the answer actually matters, use Compare modelsin the composer instead of picking one and hoping. Send the same prompt to two or three models, see the responses side by side, and let whoever's in the session weigh in on which one to go with. The choice gets recorded, so the reasoning behind it doesn't disappear once the conversation moves on.
A heavier model isn't just slower β it costs meaningfully more in credits per response, since output tokens especially are priced higher on frontier models. If your team defaults to the priciest model for everything, you'll burn through a monthly credit allotment far faster than expected. Switching to a lighter model for routine questions and saving the expensive one for what actually needs it is the single biggest lever for stretching your budget.
For the mechanics of switching models and reading credit costs, see Comparing AI models side by side and How credits work.