Claude · Settings Guide

Stop guessing.
Use the right setting.

Three little controls live in one menu next to the send button.
Learn them once, then just pick a preset.

The Three Controls

MODEL
How clever the base brain is.
Haiku — quick & basic Sonnet — smart all-rounder Opus — heavyweight reasoner
EFFORT
How thorough it is on this answer.
Higher = deeper and slower, and it uses up your plan's limits faster.
Lowstretches usage
Mediumroutine
Highbest balance
Maxhardest tasks
THINKING
Whether it shows its working first.
A separate toggle — mix it with any effort level you like.
Off — answers straight away / On — reasons it through first

Where To Find Them

1
Click the model name next to the send button.
2
Pick your model (use "More models" for the full list).
3
Click "Effort" and choose a level — the recommended one is marked "Default."
4
Hover "Effort" and flip the "Thinking" toggle on or off.
🟢 Everyday Most of what you do
Emails & messages Calendar & quick tasks Recommendations Summaries & quick questions
Settings Sonnet 4.6 Effort: Low–Medium Thinking: Off
🟡 Turn it up When it matters a bit more
Important drafts Planning & analysis Comparing options Anything you'll act on
Settings Sonnet 4.6 Effort: High Thinking: On
🔴 Heavy work When being wrong costs money or causes a mess
Tax & financial logic Legal or structuring questions Cross-checking & proof-reading High-stakes decisions
Settings Opus 4.8 Effort: High or Max Thinking: On

The One Rule

Leave it on Everyday by default. Only reach for Heavy work when being wrong would cost you money or cause a mess. You can change any of the three settings mid-chat — it applies to Claude's next reply.

💡 Worth Knowing

Running Opus on Low effort with Thinking off throws away most of what makes Opus powerful. If you're going light, Sonnet gives you nearly the same answer faster and uses fewer of your plan's limits. Save Opus for when you actually let it think.