Claude Clue #20: Effort Is the New Thinking

If you've been using Claude Code for a while, you might remember manually toggling between thinking modes or typing 'ultrathink' when you needed the model to really chew on a problem. Anthropic has layered a new control on top of all that: "effort" levels. Claude 4.6 introduced four (low, medium, high, max), and 4.7 just slotted in a fifth called "xhigh" — sitting between high and max for long-horizon coding and agentic work. Same model, different gears. The tradeoff is straightforward: lower effort means faster responses and fewer tokens burned, while higher effort means more time to plan, reason, and explore. Worth noting — ultrathink still works as a per-prompt nudge when you want extra reasoning on a single turn without changing your session default.

Here's what this looks like in practice: when you run `/model` in Claude Code, up/down arrows pick your model and left/right arrows adjust the effort slider. After some back-and-forth in March, the current defaults are xhigh on Opus 4.7 and high on Opus 4.6 / Sonnet 4.6. So if you've got a gnarly refactoring task and you're not in a rush, crank it to max and let it think. If you're just renaming variables, dial it back and save the tokens. It's a nice bit of fine-tuning that lets you find your own sweet spot between cost, speed, and capability.

No robots were harmed in the making of this clue.

This one took all three of us, Roscoe, Christopher and Jaws!