Claude Sonnet 4.6: Speed and Affordability for Everyday Tasks

The Default Choice

Sonnet 4.6 is what you should default to for most development work. The cost is roughly half of Opus models, and for the majority of tasks — writing functions, tests, API integrations, bug fixes — the capability difference from Opus is negligible or nonexistent. You are paying a premium for reasoning capability you do not need on tasks where the answer is straightforward.

Where Sonnet Excels

Sonnet 4.6 handles straightforward development tasks extremely well. If you know what you want and can describe it clearly, Sonnet will produce good code without the slower, more expensive reasoning process that Opus uses. For tasks where the solution is clear to you, Sonnet is the right choice.

Where Sonnet Shows Limits

Sonnet can be confidently wrong in ways Opus would catch. On complex debugging tasks with non-obvious root causes, on architectural decisions with competing tradeoffs, and on tasks that require maintaining coherent state across very long contexts, Sonnet will more often produce plausible-but-wrong answers that you have to catch and correct. When you find yourself correcting Sonnet repeatedly, switch to Opus for that task.

Use Cases for Sonnet

• Feature development — straightforward implementation tasks
• Test writing — where you know what the expected behavior is
• Bug fixes — where the bug is localized and the fix is clear
• Code review — identifying obvious issues and improvements
• Refactoring — where you know the target structure