Choose a model and effort level

When you open Claude, a small menu near the message box sets which version of Claude answers and how much effort it puts in. Most days the defaults are fine. Knowing when to change them is what gets you a quick answer on the small stuff and a stronger one on the hard stuff.

The model is which version of Claude you are talking to, and they trade speed for depth. Claude names them by size. Haiku is the fast, light one. Sonnet sits in the middle. Opus is the most capable and the slowest. The menu describes what each is good for, so you can choose by the description rather than the name.

The effort level is a separate control for how hard Claude works before it answers, from quick to more thorough. A quick setting is right for a rewrite, a short summary, or a straight question. Turning it up makes Claude take longer and work through the problem more carefully, which earns its keep on analysis, a multi-step task, or anything where being right matters more than being fast.

Both dials point the same way. A heavier model and a higher effort take longer and use more of your plan's usage, which the next lesson covers. So match the setting to the task: reach for depth when the work is genuinely hard, and leave the quick defaults in place for everything else.